DIRECTED ENERGY FUTURES 2060 Visions for the next 40 years of U.S. Department of Defense Directed Energy technologies Approved for public release; distribution is unlimited. Public Affairs release approval # AFRL-2021-1152 This document was authored by the Office of the U.S. Air Force’s Chief Scientist for Directed Energy, Air Force Research Laboratory, for the Office of the U.S. Secretary of Defense’s Directed Energy Community of Interest. We are grateful for contributions from the U.S. Naval Research Lab, Office of Naval Research, U.S. Army Space and Missile Defense Command, Joint Intermediate Force Capabilities Office, other components of the Department of Defense, Los Alamos, Sandia and Lawrence Livermore National Laboratories, collaborators from industry, academia, and international partners affiliated with the North Atlantic Treaty Organization (NATO). Table of Contents Executive Summary iii 1. Introduction 1 2. Trends 4 2.1 Directed Energy Range and Focus of Military Power 4 2.2 Directed Energy Scalability and Flexibility in application of power within phases of conflict 9 2.3 Precision of Directed Energy Weapons in special operations 15 2.4 Directed Energy Weapons for intermediate forces operations 18 2.5 Speed of application of power within the battlespace 20 2.6 Directed Energy platform concerns and affordability 23 3. Futures States 25 4. Recommendations and Conclusions 29 5. References 31 6. Appendices 35 A. Future State Vignettes 35 B. Participating Organizations 41 C. 2060 Assumptions 42 D. Acronym List 43 E. Description of Units of Measurement 44 We maintain that we are approaching or have passed a tipping point for the criticality of Directed Energy (DE) capabilities as applied to the successful execution of military operations for the United States, Allies, and for the United States’ rivals and potential adversaries. DE is a focused beam of electro-magnetic energy that is used to enable or create military effects, when used in conjunction with other military systems, including kinetic weapons. Specific examples of DE are lasers, radio frequency devices, high power microwave, millimeter wave, and particle beam technology used to create a military effect, e.g. deny, degrade, damage, destroy, or deceive. A growing number of nations, are realizing the potential of DE for a variety of militarily relevant missions. At least 31 nations today have DE weapons for counter unmanned airborne system (c-UAS) missions, such as base defense. Other examples of pervasive DE technologies include pointer and illuminator lasers. Today both state and non-state-actors have used low-power lasers during operations: military, policing, during protests, and to imperil civil and military pilots. Counter sensor and counter electronic DE weapons are effective today from a variety of platforms (airborne, ground, and ship based), across various phases of war and intensities of conflict. Recognizing the increasing military criticality of DE capabilities, we are moving aggressively to retain U.S. DE leadership. This increase in DE military significance is driven by convergence of trends in: • The science and technology enabling greater DE performance and capabilities • The characteristics and requirements of offensive and defensive operations across the battlespace, and • The role and characteristics of information in maintaining military parity or dominance across the battlespace. The increased criticality and competition of DE capabilities argues for a national strategy that guarantees U.S. DE military capabilities ensuring U.S. national interests and power. Such a strategy must incorporate short-, mid- and long-term perspectives on the future of DE capabilities both generally and specifically as they apply to military operations. This report presents results from the first of a three-step effort to provide that long-term vision towards the development of this strategy. The other steps will be completed in subsequent workshops. The three steps are: (1) Describe a range of possible Directed Energy future scenarios and explore the characteristics of those scenarios and their implications for national and military power. (2) Understand the drivers and inflection points for those scenarios most advantageous and disadvantageous to the U.S with respect to national defense. (3) Determine the minimum essential capabilities and actions required to implement a Directed Energy strategy meeting military needs. For the first step, the DoD Directed Energy Community of Interest and the Air Force Research Laboratory Directed Energy Directorate, hosted a DE Futures 2060 Workshop in October 2019, to explore the status and role of directed energy capabilities 40 years into the future. The participants, comprised of DE experts from several agencies and services in the DoD, DoE, NATO, industry, and academia. The assembled experts assessed the historical and current state of DE technologies, and used those assessments to forecast DE technology, relevance, and proliferation into the future across a range of militarily relevant principles. They used an alternative futures analysis technique to develop a range of future scenarios and to explore how they relate to national power. This document summarizes and expands upon those discussions. The workshop explored potential DE futures along three axes: Advancements in DE systems performance: What performance can Directed Energy systems provide based on advances in DE science and technology? Prevalence of DE capabilities: How widely and at what level are Directed Energy capabilities proliferated across nation states and other entities? Military significance of DE enabled capabilities: What is the military utility of DE enabled capabilities in the execution or disruption of the kill chain, across domains and across the phases of conflict? Along each of these axes or dimensions, the workshop participants defined three states bounding the potential futures for Directed Energy in 2060: optimistic, conservative, and pessimistic. These states were carefully developed to realistically span the range of possible future states, and to avoid the pitfall of wishful thinking as to the state along any axis. Combinations of the states along the axes or dimension, produced 27 possible futures. A subset of these futures were developed in more detail to determine their implications to U.S. power and to the development of a national DE strategy. A sufficient number of the futures were examined to determine the full range of possible threats and opportunities for U.S. military power. The specific futures examined were: Future 1 Prevalence, Technology, and Military Utility all Optimistic Case Future 2 Prevalence, Technology, and Military Utility all Pessimistic Case Future 3 Prevalence, Technology, and Military Utility all Conservative Case Future 4 Technology, and Military Utility Optimistic Case, Prevalence Pessimistic Case Future 5 Prevalence and Military Utility Optimistic Case, Technology Pessimistic Case Future 6 Prevalence Conservative, Technology Optimistic Case, and Military Utility Pessimistic Case Examination of these futures and their implications led to the following preliminary conclusions: 1. The U.S. and its close Allies increasingly rely on electromagnetic superiority to maintain operational communications and avoid detection. Therefore, we are approaching (or have passed) a tipping point in the criticality of directed energy capabilities to successful military operations for the U.S., Allies, peer competitors, and potential adversaries. 2. Our potential adversaries and rivals will increasingly challenge U.S. leadership in DE military capabilities. 3. This increased criticality and competition argues for a national Directed Energy strategy to ensure that the U.S. has the DE-enabled military capabilities required to protect our national interests in 2060. 4. The future state methodology ensures that an appropriate range of futures are considered that avoid the historic tendency for the DE community to overpromise in terms of the maturity of DE technology, and underperform as to the operational capability that DE can provide. 5. Even with a pessimistic estimate of the advance in DE science and technology, DE capabilities will have significant military utility in the battlespace of the future, due to the unique capabilities of DE systems in terms of precision, range, flexibility, scalability of effects, deep magazine, and active probing of the battlespace across all domains and phases of conflict. Today, DE weapons are used by all major military powers for a variety of effects. 6. The increase in military significance of DE systems depends on the ability to convert technological advances into operational capabilities. Technical challenges remain, that require research and development, as well as consideration for all elements of the DOTMILPF and life-cycle management. 7. Under conservative or optimistic projections of advances, DE capabilities will be a vital contributor to military operations within, and across all domains for the U.S. and its potential adversaries. Because the pace of conflict is forecast to quicken, certain counter-air operations of the future may only be possible with the speed advantages DE offers. 8. World-wide trends hint at a flatter economic and technological world in 2060. While the U.S. desires to retain its dominant position in DE operational application, science and technology, this position will be difficult to maintain with a large set of peer competitors. 9. For all futures examined, DE military applications will be sufficiently important that lagging behind peer competitors in areas of DE military capabilities risks the U.S. military’s ability to project power and protect national interests. 10. The most probable, achievable state for the U.S. in 2060, is parity in DE science and technology and operational capabilities with the expanded set of peer competitors. The importance of assuring this parity is directly proportional to the level of proliferation of significant DE military capabilities and the level of increased performance, enabled by advances in DE science and technology, by those nations who lead in DE. 11. The key challenges in developing a strategy to assure those futures with the U.S. having at a minimum, parity with peer competitors are: a. Determining the breadth and focus of investments across the complex space of DE science and technologies with potential for military applications. b. Developing the human capital needed to perform the science and technology and engineering, required to transition the technology to operational capability. c. Ensuring the ability to adjust quickly to new advances or breakthroughs. d. The ability to rapidly convert those advances or breakthroughs into operational capabilities, ideally asymmetric capabilities, so as to match or outpace our competitors and potential rivals. 12. This first workshop and associated report provide a vision, valuable initial inputs for the refinement of the national strategy for Directed Energy, and argues strongly for continuation of the efforts, as critical inputs to national strategy development. Directed Energy (DE) is defined for military applications as the ability to project electromagnetic energy either broadly to provide information probing of the battlespace, or in a focused manner sufficient to produce a defensive or offensive effect at militarily relevant distances within the battlespace. The military significance of Directed Energy Weapons (DEWs) has long been recognized for ability to engage at the speed of light, propagating vast distances with precision. Other benefits include potentially deep magazines, meaning the capability to fire many shots without need to physically rearm the weapon, and low cost per shot. DE can also actively probe targets and threats, i.e. laser pointers (commonly called designators), laser and radiofrequency (RF) tracking, also called radar. The final benefit worth mentioning, is the ability to cause scalable and flexible effects, to include destructive, damaging, disruptive, non-lethal, deceptive, and unattributable effects. Today in the early 2020s, world-wide DE already plays important military roles in counter-air defense, target identification, tracking, counter intelligence search & reconnaissance (ISR), and electronic warfare (EW). U.S. military thinking on electromagnetic spectrum operations defines DE in the context of electronic attack systems designed to disrupt or degrade an adversary’s signals, deliver communications supporting cyberspace operations, or disable and destroy targets susceptible to high-energy electromagnetic radiation (U.S. Joint Chiefs’ of Staff 2020). Today there are historical definitions that delineate DE and EW weapons which are otherwise similar in function and form. Because the historical definitions are unlikely to be important 40 years in the future, in this report we considered DE and EW weapons to be synonymous, especially with respect to applications of information superiority that rely upon electromagnetic spectrum superiority to accomplish military missions. The electromagnetic spectrum of light spans frequencies, starting at a few Hertz (1Hz=1 oscillation of the electromagnetic field of light per second), the frequencies at which modern electrical infrastructure operate. The spectrum continues through radiofrequencies, microwaves, and millimeter waves, at which most modern communication systems operate, and then through the infrared, visible, and ultra-violet (UV) that are often referred to as the optical part of the spectrum. Finally, the most rapidly oscillating frequencies are X-rays and gamma rays. Because most modern electrical and communication (e.g., cell phones, computers, radios) systems operate in the few Hz through optical frequency ranges, DE plays a vital role in the global technology of this and future eras. While the power of light is still considered mysterious by many people, and DE systems still considered the devices of science fiction, today DE systems commonly exploit the electromagnetic spectrum. They are of military and commercial utility, and pervasive in manufacturing and medical sectors of modern society. For example, in the early 2020s, specifically as of March 2021, the U.S. death toll from the COVID-19 pandemic has already surpassed the combined total number of American military service member lives lost during combat in World War I, II, and the Vietnam War. UV lights and other forms of light are standard equipment for sanitizing medical equipment and ventilation systems, helping to prevent spread of the disease. Although DE is most certainly not a cure-all, there are other technologies on the horizon that make use of the power of light in perhaps surprising ways. For example quantum-information can be encoded on pulses of laser light, enabling higher security communications. In another example, there are projects underway in the U.S. (U.S.A.F. 2019, Mosher 2018) and in China (Rosenbaum 2019) that use DE to transport or “beam” power to remote and disadvantaged locations. Looking to anticipated future trends, it is our assessment that in a conservative forecast of the future, applications of electromagnetic spectrum dominance are likely to create significant asymmetric military advantages. A historical example of DE that also shows the flexibility DEWs provide to information superiority operations, is the example of illuminator lasers, also called designators, and colloquially laser pointers. These laser devices illustrate how DE can be used to create a spectral asymmetric advantage over one’s adversaries. Countless military victories in Iraq and Afghanistan during the past 20 years, relied on infrared sensors and night vision goggles, used in conjunction with infrared laser illuminators to dominate adversaries on the ground and from the air. U.S. and Allied forces “owned the night” by domination of the infrared portion of the electromagnetic spectrum, in high intensity conflicts (Eason 2003). DE is uniquely suited for several missions in a strategy for layered defenses and information superiority, by means of electromagnetic spectrum superiority. Notions of layered defense have long been a focus of U.S. military investment and are expected to increase, evolve, and solidify as offensive threats increase, evolve, and pose more risk. The challenges of electromagnetic spectrum superiority have been noted by the U.S.’s most senior leadership (U.S. Department of Defense 2013, President Obama 2010). We argue that due to the convergence of trends in technology and the evolution of the battlefield, DE military capabilities have reached or passed a tipping point in their criticality to the successful execution of cross domain, military operations by the U.S., Allies, and current and potential rivals and adversaries. Recognizing this fact, these entities are challenging U.S. leadership in military DE capabilities. This convergence of trends and increased competition, argues for a focused national strategy for Directed Energy to ensure U.S. leadership sufficient to protect our key national defense interests. Such a strategy must incorporate short-, mid- and long-term perspectives on the future of DE capabilities, generally and specifically, as they apply to military operations. To provide this long-term perspective and to drive the development of the needed national DE strategy, the Office of the Secretary of Defense (OSD) Directed Energy Community of Interest and the Directed Energy Directorate of the Air Force Research Laboratory are executing a 3-step process. The 3 steps in this process are: 1. Describe a range of possible future Directed Energy scenarios and explore the characteristics of those scenarios and their implications for national and military power. 2. Understand the drivers and inflection points for those scenarios most advantageous and disadvantageous to the U.S. with respect to national defense. 3. Determine the minimum essential capabilities and actions required to implement a DE strategy meeting military needs. Although we can only speculate about the future world of 2060 (see Appendix A for three fictional vignettes), the process we utilized follows one developed by NATO, and borrows from the Shell Oil Company’s alternative futures analysis technique (Henchey 1978, Schwartz 1991, Bishop 2007, Rizzo 2018, NATO Strategic Analysis Branch 2017). Interestingly, the April 2020 issue of National Geographic adopted a similar methodology to future cast the world in 2070. Future casting is part of the first step in a NATO Defense Planning Process (NDPP). To address the first step, a two-day workshop was conducted at Kirtland Air Force Base on 17 and 18 October, 2019. The participants in the workshop consisted of a wide range of DE experts from the DoD, DoE, NASA, NATO, industry, and academia (see Appendix B), each representing different sub-areas of expertise as well as various mission areas. The assembled experts shared a rich knowledge-base of the historical trends in DE, the now state of DE, and a vision for the future. Further steps in the futures planning process will be addressed in future workshops. Using the three dimensions, Science and Technology (S&T) advancement, prevalence, and military utility, we discuss historical and current day (the early 2020s) trends affecting the future of Directed Energy out to 2060 as an element of national and military power. These trends are discussed in greater detail, in six subsections according to the performance that DEWs enable: 1. Range and focus of military power – either broadly for information purposes or narrowly as required for defensive and offensive operations. 2. Scalability and flexibility of application of power within phases of conflict. 3. Precision applications for special operations. 4. Precision applications for non-lethal operations. 5. Speed of application of power within the battlespace – How fast can DE engage targets in a battlespace? 6. Platform considerations of size, weight, and power (SWAP) and affordability In the following subsections, we discuss historical developments and current day status with specific, well-documented examples of DEW technology. We explore three technical areas: laser systems, high-power electromagnetics (HPEM), which includes radio, microwave, and millimeter-wave weapons, and the DE tech area of particle beams. Each is described with respect to the performance characteristics and expected trends forecast over the next 40 years. Either broadly for information purposes or narrowly focused as required for defensive and offensive operations, the ability to project power with DE derives from the ability to create effects at range. For example, lasers can burn holes or otherwise damage material by increasing its temperature above its melting point. RF enables information dominance by disrupting communications as will be described in Sec. 2.2. Material degrading DE effects include counter-electronic and counter-sensor effects, both of which will be discussed in greater detail in Sec. 2.2-2.3. At range DE can be used to destroy or degrade material through absorption, which includes effects such as damaging sensors or the human eye, an offensive technique used by non-state actors today in operations, such as intermediate force actions that deny people access to point locations (see Sec. 2.4). Laser weapons can also cause damage by igniting fires. All together Directed Energy Weapons cause all 5 of the well-known “D’s”— destroy, damage, degrade, deny, and deception— in addition to other strategic effects identified in the U.S. Joint Chiefs’ of Staff DoD Dictionary. In the rest of this section we will focus on the blunt effects of physical damage and destruction as a means to project military power at range. The power of DE to burn holes in material by heating it to temperatures at which it melts or otherwise structurally breaks, is a power that is uniquely suited for lasers. For a few every day examples of high energy lasers that melt metal, consider welders and laser etchers. Both high-energy laser devices are common place equipment in industrial applications today. These laser devices are proliferated around the world. Lasers have found use in these applications because the physics of heating a hard material, such as metal to its melting point favors frequencies at which the material most effectively absorbs light. Those frequencies are typically in the UV, optical, and infrared parts of the spectrum, all of which, are suited to laser production. Laser light can be focused very tightly as well, literally focusing destructive energy on a potential target. And it has other unique characteristics, such as potential long-range characteristics that we will explain further throughout this document. Historical and Current Examples of High Energy Laser Technology: Although today high-energy laser equipment is proliferated worldwide, the ability to create laser effects at vast ranges, for military purposes, is still limited. Today, for reasons that we will explain further, it is thought that two of the most militarily relevant use cases for high-energy laser weapons are i.) high-altitude (greater than 30,000 ft.) operations where the stand-off range between shooter and target is up to hundreds of kilometers, or ii.) ground- or sea-based defensive purposes. In 2020, it is possible to build a 100’s of kilowatt class laser weapon system that can create destructive effects at tactically relevant distances, which if deployed could enable certain offensive and defensive operations. By tactically relevant distances in this instance, we mean up to a few kilometers. Today, depending on laser energy level, hardness of the target material, and range between weapon and target, a laser weapon can create a destructive effect at tactically relevant distances by focusing precisely on a target for up to several seconds (Rehberg and Gunzinger 2018). The military utility of laser weapons has been proven through live fire testing, including for counter-air missions, the importance of which we will stress throughout this report, (88th Base Wing Public Affairs 2019, Chuter 2019, 88th Air Base Wing Public Affairs 2020, Altay, İbrahim, Ed. 2019, Lye 2020, GeoPolitics News 2020) and through mission-level weapons modeling and simulation. Historically, and today, there are several well-known concepts for high energy laser weapons systems produced by the U.S., Allies, and potential rivals and adversaries world-wide. For example there are several airborne laser programs (Missile Defense Agency 2010, Mizokami 2020, 88th Base Wing Public Affairs 2019, Mayfield 2019, S. Freedberg 2020) and space-based laser concepts (Missile Defense Agency 1997, Kornilov 1993). Both ground-based (Mizokami 2019, 88th Air Base Wing Public Affairs 2020, S. Freedberg 2020, SRC, Inc. 2018, Ahval 2019, Altay 2019, GeoPolitics News 2020) and ship-based (Lendon 2020, Associated Press 2020, Chuter 2019, Cronin and Neuhard 2020) high energy laser weapon concepts have been demonstrated to a high technical readiness level (TRL) and maturity levels in specific mission areas, such as against small and relatively soft targets. Today these laser weapons cause destructive and damaging effects at militarily relevant ranges. Furthermore, there is wide proliferation of laser weapon technology. As of 2020, at least 9 of the top 10 largest military powers in the world have publicly announced laser-based weapons programs. It is not clear if all of those programs specifically intend to cause mechanical failure of materials, or less lethal effects which we will discuss further in Secs 2.2-2.5. It is clear that many are counter UAS systems. There are publicly released videos of a Turkish Army ROKETSAN laser weapon system destroying small UASs (Altay 2019). Although the first known successful counter-drone DE experiments were conducted by the U.S. under Project Delta, in 1973, reports indicate that in 2019, the Turkish military used a laser weapon to destroy a UAS during conflicts in Libya. If true, this is a first of its kind combat achievement (Ahval 2019). Future Trends and Challenges for Laser Weapon Technologies: To understand the future technical trends in lasers system development, one must consider the drivers behind laser technology in the last 40 years. Technical trends over the next 40 years will be driven by both military and commercial interests, in addition to the lessons learned from previous laser weapon programs. Some of the lessons learned from the U.S. Airborne Laser Program, which began about 40 years ago and used gas and chemical laser architectures, were i.) the logistical footprint of a laser can create operational challenges; ii.) maximum powers in the range of Megawatts can be attained; and iii.) control of the beam is vitally important and nontrivial to achieve with highly accurate pointing. The challenges of beam control include propagation of light through potentially turbulent atmospheres, compensation of mechanical jitter from the host platform (in this case, the airplane), and C4ISR integration. Today the U.S. Air Force continues development of a high energy laser on a tactical airborne platform (Insinna 2020). The U.S. DE community has made significant progress toward addressing the lessons learned from early programs. Presently, the U.S. and Allied DE community uses a solid state and fiber optic laser architecture both because they learned the lessons about the logistical footprint of laser systems, and due to the industrial development and commercialization of fiber-optics and other solid-state laser technology. In fact, commercial development has revolutionized laser technology over the past 40 years. Solid state and fiber-optical approaches eliminate the need for large volumes of toxic chemicals in DE systems. Furthermore, fiber lasers can be combined to produce hundreds of kilowatts of power, with good beam quality (Anderson 2015), and have proven relevant in tactically suitable payload sizes, weights, and powers (SWAP). Many of the trends in high energy laser technology development are driven by global commercial market forces. Over the next 40 years, solid state and fiber laser architectures will undoubtedly advance through continuous improvement in engineering processes with trillions of dollars of investment in international industries such as the communications, information, integrated photonics, and even commercial electronics industries. These industries are likely to drive the advancement of laser technology in the next 40 years, more than military applications will advance the technology. Fortunately, investments that are driven by militarily unique requirements appear likely to reap the benefits of industrial development such that even in a pessimistic view of the future, one can easily contemplate reduction in SWAP that would make airborne, space-based, and all domain DE missions more viable by 2060. Conservatively, following trends of the past 40 years of development up until now, in the future, solid-state and fiber laser technology can be projected to achieve extremely high energy levels in the range of Megawatts over a second, high enough to reduce timelines for laser engagement to less than 1s at tactical ranges by 2060. Optimistically, 100’s of Megawatt solid state laser systems could be possible. This technical trend is bolstered by current research in laser power scaling (Sherman 2019), to reduce dwell times and/or increase range of effects. For laser weapon technologies, these advancements represent an inflection point as they reduce the timescales of engagements significantly, enabling vital missions. Once a sufficient amount of laser energy is created, the next challenge for laser weapons lies in the ability to propagate laser energy kilometers or farther distances, through the atmosphere, to targets at range. Trends in technology development over the next 40 years will be driven by solving such challenges. The challenge includes both tracking of moving targets at high levels of accuracy from moving platforms, and being able to control the beam both accurately and precisely. Today, lasers weapons are powerful enough for missions against soft targets such as UASs (88th Air Base Wing Public Affairs 2020, Chuter 2019) and demonstrations of counter-missile applications (88th Base Wing Public Affairs 2019). State-of-the-art beam pointing from stabilized gimbal mounts permit hundreds of nanoradian precision pointing from stationary and slowly moving platforms, while tracking fast moving objects (Kwee 2007). Microradian accuracy is currently possible on large airborne platforms. In the future, by 2060, higher pointing accuracy, approaching 100s of nanoradians, could optimistically be possible on fast moving platforms. Invention of solutions to technical challenges will drive future trends. For example, propagating laser energy through the atmosphere, becomes challenging in poor weather or turbulence. Turbulence causes both beam wander and brightness fluctuations in high energy lasers. Weather deleteriously effects all weapons, but poses particular problems for all optical and infrared sensors, many of which provide cues and tracking for command and control of weapon systems. Inventions over the next 40 years may prove the ability to overcome weather effects. As an example, current research focuses on ultra-short pulse lasers that promise to burn holes through fog (Rudenko 2020). A technology that today compensates for the deleterious effects of atmospheric turbulence is adaptive optics, invented and developed nearly 40 years ago (Fugate 1991). Sophisticated adaptive optical systems can today compensate for moderate levels of turbulence and atmospheric distortions. Conceivable improvements in the engineering of optical systems, even in the most pessimistic case for technology advancement, will further improve efficiency in ability to put up to Megawatts of continuous wave laser energy on target at tactically relevant distances. Gigawatts or 100s of Megawatts of laser energy propagated at tactically relevant and longer distances, would be an optimistic technical outcome by 2060. In the atmosphere, power levels greater than a few Gigawatts would undoubtedly suffer from self-focusing effects (Nibbering, et al. 1997). U.S. DoD and Allied military utility studies have been conducted, and will continue to be conducted, to objectively determine, in conjunction with kinetic and cyber weaponry, to what degree of effectiveness DE capabilities can achieve destructive effects for specific missions and scenarios that include weather. An easy way to avoid the issues of weather and atmospheric propagation is to deploy DEWs at high altitudes, where the earth’s atmosphere is thinner. For this reason and others, high altitude military applications of DEWs will remain important concepts into the future. Future trends in DEW technology will follow mission needs. The “holy grail” from a military utility perspective is a DE weapon system effective enough, favorable from a SWAP perspective, and affordable enough to provide a nuclear/missile umbrella. Although a concept often associated with science fiction, in fact ground and ship-based DE defense systems effectively act like point-localized force fields against small and relatively soft targets today. Airborne and space-based DE platforms could achieve a greater area defense and multipoint defenses, for a broader coverage missile umbrella. However, these concepts require significant technical advancement by 2060 to achieve the full range of power contemplated. Albeit significant technical advancements are required in power, and range of power specifically, in the most optimistic case it should be physically possible to design a mission relevant concept of operations that permits nanoradian beam-control accuracy while tracking missiles up to hypersonic speeds, with a fast enough command and control loop and Megawatts of laser power. By 2060 a sufficiently large fleet or constellation of high-altitude DEW systems could provide a missile defense umbrella, as part of a layered defense system, if such concepts prove affordable and necessary. Future trends in range and focus of military power will be driven by new mission areas. Recently, the Arctic has become more contested and congested. The Russian Navy has therefore initiated Project 23550 to build laser weapons to melt ice, helping their ice breakers advance further and faster (Yurov 2020). In addition to destructive effects described in Sec. 2.1, DE provides options for what many refer to as dialable or scalable effects. Associated with dialable effects is flexibility in application of power across the leading phases of conflict, from shaping of the battlespace, deterring aggression, and domination of the electromagnetic spectrum (U.S. Joint Chiefs’ of Staff 2018). DEWs provide these options by causing effects in militarily relevant scenarios. Low levels of laser light, millimeter waves, microwaves, radiofrequencies, and particle beams can all be absorbed in materials through processes fundamentally different from hole burning described in Sec. 2.1, but with known and potentially devastating effects. These effects include: • Causing destructive fires • Counter informational and specifically, counter ISR missions such as jamming, dazzling, infrared and radar counter measures that degrade, disrupt, and deceive sensors and electronic systems that are highly susceptible to specific frequencies of light • Denial by non-lethal repelling, long-distance hailing, and ground base defense missions (Office 2020) • Disruptive and destructive offensive operations from airborne platforms (Mayfield 2019, Chen and Zhou 2019) • Disruptive and damaging counter electronic effects for defensive counter-air missions and establishment of point defenses (Michel 2019, Mayfield 2019, Cohen 2019, Robinson-Avila 2019). Historical and Current Examples of High Power Electromagnetic (HPEM) Weapons: Both high and low power/energy effects of DEWs are well known today. There are many examples of effective technologies in the class of DEWs called High Power Electromagnetics (HPEM), which include millimeter wave devices, high power microwave (HPM), and radiofrequency devices. Additionally, devices frequently called electronic warfare (EW) jammers create counter-electronic effects at both tactically relevant distances, such as kilometers, and at closer ranges suitable for special operations or gray zone warfare. Electromagnetic jammers are so widely proliferated and militarily useful that in 2020 they are considered standard equipment in the arsenals of all major military powers, including the U.S., NATO, Western European militaries, Russia, China, and several other military powers in Asia (Hamamah 2017). Russia and China have well known anti-access and area denial capabilities based on both kinetic and EW defenses (S. J. Freedberg 2019, Yeo 2020). Especially for non-lethal applications, such as electronic attack and electromagnetic spectral dominance, both of which play key roles in shaping and dominating the battlespace, these weapons are clearly militarily useful today. While EW jammers can degrade a target’s ability to operate, HPM weapons can degrade, damage, and effectively destroy a target. HPM has demonstrated scalable militarily relevant effects. When used in concepts of operations that benefit from convergence of effects, cyber, EW, HPM, and traditional, kinetic weaponry together provide flexibility and scalability in application of power across all phases of conflict. High power microwave weapons are typically characterized as generating electromagnetic radiation of frequencies ranging from 300 Megahertz – 300 Gigahertz, and with peak power over 100 Megawatts (Chen and Zhou 2019). Electromagnetic energy absorbed in this range induces electric currents in electronic devices that may result in either a disruption or failure of the electronics, and in extreme cases, physical damage. Research and development of HPMs began in the 1970’s and has only accelerated with the proliferation of electronic systems. Almost every aspect of modern civilian and military daily operations incorporates electronic systems: in almost every facility, including communications facilities and networks, control centers for power grids, cell phones, ATMs, and even household appliances. HPEM and RF DEWs that attack these pervasive electronic systems offer flexibility and scalability in a range of missions and from a range of platforms today. Gigawatt vacuum-tube HPM systems have been demonstrated. At Gigawatts of power, an HPM device can break-down air which adversely effects the ability to propagate the directed energy long distances. The upshot is that for applications in the atmosphere, a breakthrough in the ability to generate more power is not necessarily needed. However, a technological breakthrough in the capability to propagate directed energy through the atmosphere could help achieve greater on-target power levels and increase effectiveness. High power vacuum-tube based technologies, are typically quite large. Hence, vacuum-tube based HPM systems are often ground- or ship-based systems with meters wide high-gain antennas that focus the DE at tactically-relevant ranges of effectiveness on the order of 1 km. Although HPM counter-electronic effects are clearly demonstrated, surprisingly the actual modes of electronics failure are poorly understood at a basic physics level and are active areas of research in 2021 (Clarke 2019, Cui 2019, Dietz 2019, Lawrance 2017, Peng 2017). As researchers in these areas discover the physical mechanisms behind counter-electronic effects, it is possible that by 2060, more efficient uses of HPM and counter-HPM technology will also be discovered. Other unique attributes of HPM that make it militarily useful in both high-intensity and lower-intensity phases of conflict lie in the fact that, unlike lasers or particle beams, in low doses, HPM based DE is non-lethal to humans. This is another reason that HPM remains useful for counter-electronic attack, which is of significant current-day and future military utility for both traditional and special operations. This subject of non-lethal DEW effects for intermediate force operations will be described further in Sec. 2.4. Similar to other DE systems already described, HPM is militarily useful on a wide range of platforms today. Large (tactical vehicle sized), ground-mobile systems that have moderate power (on the order of 10’s to 100’s of MW) and longer pulse duration, with antennas on the order of a few meters in size have been demonstrated for defeat of IEDs, crowd control, vehicle stopping—ground and air— and maritime vessel stopping (Office 2020, Underwood 2017, Mizokami 2018, U.S. Joint Intermediate Force Capabilities Office 2016, Rehberg and Gunzinger 2018, Robinson-Avila 2019, Cohen 2019). Today, as previously mentioned, ground-based, maritime, and airborne EW jammers are widely proliferated (Pomerleau 2020, Congressional Research Service 2019, S. J. Freedberg 2019). Larger, higher power ground-based HPM systems have also demonstrated longer range of effectiveness (10s of kilometers) for defense against aerial threats, e.g. missiles, with RF seekers. The extended ranges of such systems are achieved by designing them to operate at the same frequency as a missile RF seeker, i.e. the frequency at which the seeker is most vulnerable. Because RF seekers are very sensitive, a HPM weapon can effectively damage them. With a damaged seeker, missiles may fail to find or track an intended target, increasing the missile-targeting system probable circular error (i.e. CEP). Compact versions of HPM technology, on the order of hundreds of pounds, with moderate gain antennas have been integrated into airborne platforms, missiles, and remotely piloted aircraft (Chen and Zhou 2019). The effective DE range of these airborne HPMs remains limited, ~100 meters, but they fly long distances to cause DE effects near their intended targets. Furthermore, one airborne HPM can fire multiple times, effecting multiple targets. A perceived drawback to HPM is that the effects are often temporary. On the other hand, temporary or reversible effects offer flexibility for lower-grade effects, desirable during various phases and intensities of conflict. For example, if one were to temporarily disrupt an adversary’s communications, ground troops can overtake a facility and recover adversary data. Another example is that one could send airborne HPM weapons ahead of an air strike package to disrupt an adversary’s integrated air defenses (IADs), increasing the success of a subsequent air strike. Furthermore, in counter-missile and -UAS applications, damage can at times be permanent since the vehicles are often destroyed after falling to the ground. In 2020, driven by base defense needs, counter-UAS (c-UAS) DE weapon systems are proving highly militarily relevant for defeat of aerial threats. This includes c-UAS swarms, because the high power microwaves propagate in a conical beam that can be several degrees across or larger, simultaneously disrupting the electronic subsystems and effectively destroying multiple UASs in the beam (Robinson-Avila 2019, Cohen 2019). HPM and EW technologies have been so remarkably successful as counter UAS systems that a 2019 report issued by Bard College lists 321 EW- and HPM-based systems of 547 total known counter-drone systems, originating from 31 independent nations (Michel 2019). We predict that these technological demonstrations represent inflection points for DE technology, as they prove these systems have evident mission utility. Demonstrations to date are compelling, so much so that there is widening international adoption of DE for counter-air missions. These successes confirm the vision that DE is a game changing technology for counter-air missions (United States Air Force 2017). Furthermore, although not necessarily as imagined by science fiction, today, DEWs are effectively acting like counter-UAS force fields. Today, the most mature and operationally relevant HPM (Robinson-Avila 2019) devices are built around vacuum-tube systems specifically designed and fabricated for high power applications. The output of an HPM system typically consists of a high intensity pulse of electromagnetic energy with a specific central frequency, a finite bandwidth around that central frequency, and a duty cycle. Vacuum-tube systems are designed to be narrow-band, with a central frequency known to be effective against a target of interest. Unfortunately, duty cycles of vacuum-tube systems are inherently low, on the order of a few pulses per second. In other areas of electronics, semiconductors long ago replaced vacuum-tube based systems. Although in 2020, semiconductor HPM technology cannot deliver the robust power of vacuum-tube based technologies, semiconductor systems can be made relatively compact, for example contained within a small form factor (meters) and weighing on the order of tens to a few hundred pounds. Additionally, semiconductor technologies can have very high duty cycles and customizable waveforms. Today, semiconductor HPM systems typically have low to moderate gain antennas due to platform constraints. They are proven to be effective at defeating electronic systems at short ranges, on the order of 10s to 100s of meters. Importantly, the fact that these systems are much smaller and lighter means that they can be integrated into more agile, smaller, mobile and airborne platforms that can attack closer to the target. This fact may lead to a competitive edge over conventional HPM systems in terms of military utility. Solid-state HPM devices are also technologically important for flexibility of effects. Another promise of technological advancement using solid state systems is that they can be narrowband, mesoband, or ultra-wideband. Mesoband means that the frequency range of the transmitted energy is contained within a moderate to wide band of frequencies. Additionally, solid state amplifiers can produce narrowband through wideband pulses with waveforms that are tailorable in terms of intensity and duration, leading to sophisticated waveforms. Semiconductor-based systems have central frequencies that range from about 1 to 10s of GHz, based on their intended effects. Importantly, and unlike vacuum based technologies, duty cycles for solid state systems can be very high, on the order of 100’s to 1000’s of pulses per second. From a DEW perspective that may translate to a very deep magazine! If Gigawatt power levels can be attained in significantly smaller packages, development of solid-state HPM should help the U.S. and Allies build more efficient, more compact, and more frequency agile DEWs over the next 40 years. Future trends and challenges for HPEM weapon technologies: Because EW and HPM are useful across all phases of conflict today, we can conservatively expect they will be militarily useful in all phases of conflict over the next 40 years. As with laser-based DEWs, high power microwave-based technologies are expected to reach both a high level of technological maturity and highly relevant military utility by 2060, in even a pessimistic prediction. Research and development trends today point toward reducing acquisition and operating costs of HPM systems. Semiconductor and solid-state based systems are seen strategically as an important technology driver. Expected commercial advancements in electronics, along with advanced materials and manufacturing, are likely to drive these technologies significantly over the next 40 years. Optimistically, HPMs can be made affordable enough that the benefits of a deep-magazine, perhaps up to thousands of shots in less than a minute, and low-cost per shot will be realized. Therefore, one can conservatively expect that by 2060, DE will continue to be an effective and widely-proliferated class of weapons on a wide variety of platforms: air, space, naval and ground based. Applications of air- and space-based HPM platforms are currently the most technologically challenged because the sizes of typical vacuum-tube based high-powered microwave systems are typically quite large. In 2020, all modern concepts for conducting joint operations and most service specific concepts of operations require control of the electromagnetic spectrum during all phases of conflict. For the directed energy community, electromagnetic spectrum superiority is a must-do mission and will likely drive trends in technology, military utility, and proliferation in 2060 and beyond. Imperative mission needs for information operations (U.S. Joint Chiefs’ of Staff 2014) in the future will drive trends in HPEM across all phases of conflict, including domination of the battlespace. The U.S. and Allies should continue to develop both defensive and offensive capabilities in all parts of the electromagnetic spectrum in order to dominate that battlespace. The backbone of 2020 information systems so fundamentally rely on radiofrequency and optical signals that freedom to operate in any modern warfighting concept requires DE weapons for electromagnetic spectrum superiority (Dayton 2016). In 2020, concepts such as joint all domain command and control (JADC2) continue to be viewed as the best way to execute complex and coordinated missions of the future. Domination of the electromagnetic spectrum will be a key force enabler for those JADC2 missions. Although it is hard to imagine how technologically different the world of 2060 will be, we can conservatively predict, based on historical and current global technology trends that we will have a more internationally integrated communication system. Military applications that disrupt the power to, degrade performance of, or destroy key informational nodes will therefore be of great utility in 2060. DE will continue to be a key enabling technology for electromagnetic spectrum superiority missions, which are vital across all phases of conflict. These vital missions will drive HPEM trends over the next 40 years. Highlighting the importance of electronics in 2020 modern society, this discussion also provides a compelling argument that the U.S. and Allies should address countermeasures to cyber and DE counter-electronic threats. Today those threats can come from peer competitors, rogue states, terrorists, and criminal organizations during all phases of conflict. We must guard against the DE equivalent of Pearl Harbors, Trojan Horses, and 9-11 style attacks over the next 40 years. For future information, counter-sensor, and counter-electronic applications, considering all of the frequencies and wavelengths of DE discussed, it is an obvious conclusion that frequency agility, as part of information superiority operations will be vital by 2060 in order to operate in a contested and congested electromagnetic spectrum. Frequency agility means the ability to rapidly change the frequency composition of a DEW, either by tuning the frequency of a device, creating broad-band and tailored waveforms—where the frequency and energy composition of a DE beam varies as a function of time— or using another DEW device, in a complimentary manner. Additionally frequency agility can be used to defeat DE countermeasures and may be vital to retaining U.S. technological leadership in low-power DE missions, as well as high-power ones over the next 40 years. Building on the concepts of Sec 2.2, precision of effects is important to certain missions including special operations. One of the remarkable characteristics of DE weapons is the ability to create a precise effect. For laser weapons that includes precisely boring a hole at range, effectively destroying or disabling a target, in addition to other effects. For example: igniting fires at range, and damaging or dazzling of a sensor. HPEM DEWs create precise effects in counter electronic attacks where they disrupt, deny, degrade, and in some cases damage or destroy equipment. By their very nature, DEWs that operate in non-visible portions of the electromagnetic spectrum are often non-attributable, or challenging to attribute, because the DE beam is invisible. Since they are precisely directed and ephemeral, even with infrared, microwave, or RF sensitive instruments, it is challenging to locate the source of the DE. With these characteristics, DEWs often find utility in special or covert operations. A third example of DE weapons that we have not yet described in detail and are potentially useful for special operations are based on particle beam technology. Particle beam (PB) technologies generally fall into two sub-categories, electron or charged particle and neutral particle beams. PB concepts have the advantage that they penetrate into a material deeper than light can penetrate. Particle beam technology is known to create counter electronic effects, similar to HPM and RF technology. The characteristic of deeper penetration in materials, such as through metals that shield electronics against lasers, HPM, and RF, makes particle beams promisingly effective for applications where other DEWs are not. Due to interactions with air, PBs do not propagate far within the earth’s atmosphere. For this reason, as DEWs, particle beams are currently limited to either special operations where they can be used at close range or high-altitude operations. As with all DEW technology, the desired end result is effects on a target. In the case of particle beams, gamma and X-rays are produced as secondary radiation which causes destructive effects in materials of military relevance. Also similar to other DE, particle beams see world-wide applications in medical and industrial processing, and from that perspective particle beams are today widely proliferated. Historical and Current Examples of Particle Beams: PBs are unique because of their ability to penetrate into matter and deposit energy, frequently altering the material properties. This quality can be particularly useful when a target is shielded, such as for medical purposes, when trying to burn a deep tissue tumor, or for military purposes such as penetrating a missile airframe to disable the guidance electronics. Charged beams consist of a collection of protons, electrons, or ions. Neutrons, photons in the X- and gamma-ray portions of the electromagnetic spectrum, and non-ionized atoms constitute neutral beams. X-rays and gamma rays are also generated as secondary effects of both electron and proton beams. Protons and ions being large and charged, typically do not travel far in matter, including the atmosphere. As such, their many military applications remain unexplored. Neutrally charged atoms share these same characteristics. Currently, then, the remaining particles – electrons, neutrons, and gamma or X-ray photons – are typically considered for military application (Berger 2017, Carron 2007). Many technologies exist to accelerate electron and neutron particles up to militarily relevant energies, typically in the tens to thousands of Mega-electron volts (MeV), including RF and induction linear accelerators, neutron generators, synchrotrons, and free electron lasers, each with varying applicability to the battlefield. The first PBs were created in cathode ray tubes in the late 19th century. High energy accelerators were not invented until the 1930s. Today, non-military applications of particle beams are most common in the field of medicine, where X-ray, gamma ray, proton, and atomic ion beams are used for cancer treatment (Trikanlinos 2009). Other non-military uses include ion implantation, industrial processing, and research (Feder 2010). In the 1980s, the United States made significant investments in charged and neutral particle beams as part of the Strategic Defense Initiative (SDI), colloquially known as “Star Wars”. A significant portion of SDI investments were in the area of particle beam weapons to counter ballistic missiles. The Beam Experiments Aboard a Rocket (BEAR) project launched a neutral particle beam system onto a suborbital trajectory to test propagation theories as a part of that initiative (O’Shea 1990). High altitude applications, where the atmosphere is thinner, and space-based concepts for particle beam-based DEWs have been considered for militarily relevant use cases by both the U.S. and Soviet Union (Kornilov 1993, Whitney 2005, O’Shea 1990, Trevikthick 2019). These efforts typically focused on high-power beams, which created additional propagation challenges, and have proven to be a technology barrier at this time. Today, compared to other DEWs, particle beam weapons appear limited in military utility and proliferation. Many nations participate in the technical fields of particle physics, using particle accelerators, and the same underlying principles apply to generate particle beams for military purposes. However, many of the recent international trends in particle physics are toward larger and larger accelerators, which have less utility from a military perspective because of SWAP concerns. The particle beam community realizes that this trend cannot, however, continue. Promisingly, there is interesting research into using compact, 0.1- 4 m, linear particle accelerators (Chao 2013, Lewis 2019) for the production of radiation in the 1-100 GHz range, which, like HPM, could be used for counter-electronic purposes. Creation of efficient small particle devices, comprises a technological inflection point worthy of further research, as these low-SWAP devices would be of interest for air, space, short-ranged maritime and ground-based applications. Future Trends and Challenges for PB Weapon Technologies: Despite investments spanning several decades, PB weapons are currently unproven and significant challenges to their adoption remain. Neutron and photon beam sources in SWAP-constrained packages are insufficient to generate militarily relevant effects. In order to be militarily relevant by 2060, particle beams must propagate militarily relevant distances. Electron beams are currently considered to be the most likely to find military application, albeit that today, due to technological limitations, propagation can only be achieved poorly in the earth atmosphere. Militarily relevant systems are currently limited to less than a few hundred meters of effective range. Longer ranges are possible with higher energy electrons (~1 km at 1 GeV at sea level). The International Plasma Sciences Committee issued a grand challenge in their 2020 decadal study to improve understanding of the interactions of lasers and particle beams, to include for the purposes of advancing national security (Committee on a Decadal Assessment of Plasma Science 2020). Optimistically, the response to this grand challenge will greatly improve propagation distances within the earth atmosphere through further research investments. Other technical issues that will shape the future relevance of particle beams are that they generate ionizing radiation, meaning they pose significant risk to operators, bystanders, and enemy and friendly soldiers in the battlespace. As such, particle beam targets are conservatively anticipated to be limited to locations with carefully prescribed “keep out” zones. With these two challenges in mind, terrestrial and maritime particle beam applications are today thought to be possible, even in pessimistic forecasts, but limited to special applications where stand-off distances can be very short. At altitudes above 30,000 feet, where human exposure is less likely and the atmosphere is thinner, the outlook for particle beams is much more positive, in conservative projections. Propagation ranges for electron beams above 30,000 feet extend from hundreds to thousands of meters even for small systems. As mentioned, high altitude applications and space-based concepts for particle beam-based DEWs have been developed. Challenges for these applications include SWAP vs. electron energy and range issues, particularly the weight of systems that need to be lofted to high altitudes for long periods of time. The technological advancement most likely to be impactful for electron beam weapons in the future consists of increased acceleration gradients. State of the art accelerators today typically reach 50 MeV/m, but ongoing research into W-band RF linear accelerators promise to make 200-400 MeV/m gradients a reality in even conservative forecasts. Improvements in energy storage and conversion also conservatively promise to make electron beam weapons militarily feasible by improving their SWAP. With conservatively projected SWAP improvements, the military utility of particle beam systems at or near sea level will increase with increasing range for both special and normal military operations. Still, risk of biohazard and associated policy issues will remain, and will limit applications. If advancements in SWAP are achieved, these technological improvements will make the most difference in high altitude applications. With lighter and more powerful PB systems, airborne systems may reach higher altitudes and can remain aloft for longer durations. Should the described technological advancements be achieved, it is expected that the military utility of particle beams will increase significantly. As mentioned before, many nations participate in accelerator research, hence it is anticipated that, if driven by increasing military utility and technological capability, conservatively proliferation could rapidly increase. Pessimistically, proliferation could increase significantly. Proliferation of PB technology would pose a significant challenge, both legally and to U.S. security and military superiority in future engagements. Nevertheless, these examples illustrate how DEWs can be very precise and powerful in special and high-altitude operations, and why the U.S. should continue its investment in this area of research lest other nations take the lead. A very useful characteristic of DE weapons, especially for gray-zone warfare and in low-intensity phases of war is the ability to create non-lethal effects. Prior sections discuss these intermediate force effects in terms of counter-material effects, informational effects, counter-personnel, and for scalable effects in low-intensity conflicts. Notably, precision uses of DEWs for non-lethal operations rely on knowledge gained through rigorous scientific experimentation and understanding of the electromagnetic spectrum to produce spectrally precise effects. The human body, devices, vehicles, and structures are all composed of matter that is in some proportion either absorptive, reflective, or transparent to specific frequencies of light, the latter meaning that light may pass through with little or no effect. Exploiting frequency specific effects of absorption or transparency in matter, light can be used to generate spectrally precise militarily useful effects in specific electromagnetic spectrum frequency bands. For example, low levels of RF and microwave frequencies of light find uses world-wide for television, radio, cellphones, wireless internet, satellite and other communication signals. Moreover, these specific frequencies of light are largely transparent to materials that make-up walls and other structural components, enabling their usage for communications inside buildings and vehicles. In addition to their military and everyday utility for communications, all of the devices that generate and receive these frequencies of communication can be deceived, disrupted by jamming, or more damaging counter-electronic effects. By exploiting the absorptive properties of human skin relative to millimeter waves, a higher frequency of HPEM than RF and microwaves, a non-lethal counter-personnel effect can be generated. In another example, eye-safe, low-power infrared light can used for fiber optical communications or conversely to generate spectrally precise, deceptive false signals, dazzling, or damaging effects in infrared sensors. Because the human eye is insensitive to infrared light, at low-enough power levels it poses little danger of collateral-effects to the human eye. Alternatively, light in the higher frequency optical portion of the electromagnetic spectrum is strongly absorbed in the human eye and can be used for dazzling and non-lethal blinding. Historical and Current Examples of DE Weapons for Intermediate Force Operations: As was mentioned previously, HPEM can be used for both counter electronic attacks, and, if used in the millimeter part of the spectrum, non-lethal counter personnel operations (Office 2020, U.S. Joint Intermediate Force Capabilities Office 2016). Human skin is chiefly composed of water, which strongly absorbs 95 GHz light. The Active Denial System (ADS) produces 95 GHz DE to non-lethally heat the topmost layer of human skin, acting to effectively deny people access to locations. People have described the physical effect of this DE as like facing a roaring fire. This spectrally precise effect can be thought of as creating a force field that repels crowds around an embassy, base, port, or other high value location. The Active Denial System underwent extensive testing for effectiveness and human safety. It was also deployed to Afghanistan in 2010, but not used in conflict. The U.S. DoD Joint Intermediary Forces Directorate continues to support ADS, and concepts for application continue to be explored. Despite those efforts, the technology largely remains “on-the-shelf.” Speculation about the reasons for not deploying ADS include simultaneously and perhaps perplexingly, concerns about both safety, in other words effectiveness, and lack of effectiveness of the technology. For these reasons, ADS is often considered as an example of how public acceptance of DE technology can limit the military utility of it. Both today and in the future, this class of weapons offers unique options for security and special operations, low-level conflicts, and war in the gray-zone. The U.S., Russia, and China are all reported to have developed non-lethal ADS-like systems (Hambling 2012, Letzter 2014). Going into the future, whether or not the U.S. and Allies deploy this DE technology, it is quite possible that U.S. military members will face it in conflict. Low-power optical wavelength laser light is used today as a non-lethal weapon for dazzling and blinding humans, which is a well-known but a policy-restricted military application in the U.S. Sadly, as the U.S. Federal Aviation Administration reports, lasers have been used for criminal purposes to blind pilots, endangering the innocent lives of the flying public (U.S. Federal Aviation Administration 2019). Today, laser pointing, blinding, and dazzling are militarily useful during information operations, counter-optical and counter-infrared sensor attacks, protests, and policing operations (Cronin and Neuhard 2020, Taylor 2019). During recent protests in both Hong Kong and the nation of Chile, laser dazzlers have been used by both police and protesters. Moreover, because optical and infrared sensors are susceptible to low levels of laser light, laser illuminator weapons can achieve disruptive and damaging effects as counter-situational awareness tactics, depending on the degree of effect required at a defined stand-off distance. These militarily relevant and widely proliferated examples of DEWs are available for ground, naval, airborne, and space-based purposes today. Future Trends in DE Weapons for non-lethal operations: Spectrally precise effects across a wide range of non-lethal operations, power, and posture for acceptance of non-lethal risks remain key considerations for the U.S. and Allied nations to achieve the full promise of DEW technology for non-lethal operations. Continued effects research and development is needed to support public acceptance of intermediate force DEWs at specific power-levels and frequencies. As discussed in prior sections, there are paths to successful deployment of DEWs by the U.S. and Allies, even in pessimistic future projections. However, policy limits applications at many frequencies and power levels. Any policy must guide acceptable application of DEWs for non-lethal and all intermediate force applications, both today and in the conceivable future. Resolution of DE policy and acceptance issues represent an inflection point: if these issues can be resolved, the U.S. and Allies should continue to develop new technologies and militarily relevant capabilities, and if not, DE technologies are destined to be either stuck “on-the-shelf” or limited to niche military applications as they are today. The lamentable trend in proliferation of small lasers, even to non-state actors and criminals, is an illustrative one. It is a tragedy that, internationally, the flying public’s lives are imperiled by Class IV lasers that can easily damage the human eye, and can be purchased on the internet for less than $200. Small cheap lasers are a “poster child” for why by 2060, and hopefully sooner, better global policies on trade of DE technologies are needed. Fortunately, countermeasures to these widely available lasers can easily be implemented, albeit at increased cost. Optimistically, the U.S. and its Allies will suffer little imposed cost while strategically imposing cost on adversaries. In summary, today DE power levels are intense enough to generate effects through many non-lethal intermediate force operations that rely on exploitation of spectrally precise effects. By 2060, in conservative projections of the future we expect increases in range as power levels increase and there is tighter integration into missions that offer greater flexibility and scalability. Policies regarding usage of DEWs must be developed to guide DEW usage for military operations. In the 5th century B.C.E., Sun Tzu stated: “What is of greatest importance in war is extraordinary speed: one cannot afford to neglect opportunity.” Since extraordinary speed has been important in warfare for the past 2025 years, it is a safe prediction that speed will continue to be important over the next 40 years. In fact, the promise of greater future military power enabled by speed in a higher paced future conflict is likely to be more important in 2060. Other technology areas, including hypersonic vehicles, material and other advances in computing and electronics, advanced sensing, and autonomy, are likely to increase the pace of future conflict. Important challenges of today will remain and could be amplified in a high-paced future conflict. For example, consider the startling challenge of creating or maintaining the ability to engage multiple high-speed targets, within a targeting cycle, or within the Observe, Orient, Decide, Act (OODA) loop of an adversary’s targeting cycle, in a much more automated and advanced future battlespace. One of the greatest promises of DE is that nothing travels faster than light. Compared with traditional munitions, DEWs have a significant speed advantage. Historical and Current Examples of DEWs and Speed of Light Effects: Historical and current day examples that have been briefly mentioned but bear revisiting in the context of nearly speed of light effects include laser, HPEM, and particle beam technologies. DE weapons of sufficient power/energy levels initiate effects at a distance, at the speed of light (or for PBs, up to 99% the speed of light). However, the actual effects of DEWs may be realized over longer timescales, thus we will analyze nuances of timescales for a sensor-shooter system. To illustrate this, we discuss the stressing case for high-speed of warfare, the tactical timelines for information operations and the timelines for space-borne and airborne vehicles, where the fastest speeds are required. At the speed of light, a stand-off range of 1 km equates to initial target engagement microseconds after the shot. But this analysis alone is potentially very misleading, because DE and all weaponry require time to find, fix, track, target, engage, and assess (F2T2EA), according to the standard definition of the targeting cycle, all of which typically require longer periods of time. Numerous examples of militarily relevant informational, counter-sensor, counter-electronics, and non-lethal effects have been described in prior sections, all of which are relevant examples of the power of DEWs to rapidly engage targets in the battlespace. Although the DEW begins target engagement at the speed of light, typically the described DEWs require micro to millisecond engagement times before creating a desired military effect. In general, the time before effects occur depends on power, range, and hardness of the target. With current day electronic and computing technology, realistically a targeting cycle can at best be closed on millisecond timescales. That is assuming that the find, fix, track, target (F2T2) portion of the cycle happens at electronic speeds, i.e. milliseconds, and the time required to achieve DE effects is also milliseconds after initial target engagement. Under normal circumstances however, this would be extremely optimistic. Today, anywhere that human interaction is required, targeting cycles may be limited by human reaction times which are at best milliseconds to seconds long. Therefore, when you add it all up, finding, fixing, tracking, and targeting typically happens today over seconds-short timescales at fastest. For a concrete example, consider that the requirement for the targeting cycle for an intercontinental ballistic missile intercept is on the order of tens of minutes (Becker 2017). Counter-air missions, to include counter-hypersonic ones, are a significant and potentially existential challenge in all warfighting domains. In Sec. 2.3, particle beam DEWs and effects were described that could counter missiles on millisecond timescales, if SWAP and propagation issues were resolved. In-band laser or HPEM counter missile systems described in Sec. 2.2, are effective today at tens of kilometers, on millisecond to second timescales, depending on power, range, and hardness of the target. Although it is fortunate that these systems are possible today because they offer ability to reduce the effectiveness of missiles, there are a few practical drawbacks to using these DEWs as they require a priori knowledge of the missile seeker spectral sensitivity, they often require large platforms due to SWAP concerns, and if counter DE technologies were incorporated into seekers, the DEW effects could be rendered useless. Hence, especially when attempting to counter a missile, users often desire a blunter or otherwise more reliable effect. In Sec. 2.1, it was described that with the 2020 class of high-energy solid-state lasers, typically in the hundreds of kilowatts range, several seconds may be required to create blunt damage effects at tactical distances, i.e. structural failure in metal or other hardened materials. As laser power scales up, the necessary engagement times to create effects tend to decrease. Predicted to be possible in 2060, with optimistic advancement of solid-state laser technology, hundreds of Megawatt-power lasers can close the gap in total engagement time down to millisecond timescales, which would enable high energy laser DEWs to engage as fast as, or faster, than kinetic effectors. Compare for instance, the potentially several-millisecond DEW engagement timescales with those of a hypersonic vehicle, where at Mach-5 the vehicle covers 1 km in a little more than 1/2 a second. Promisingly, millisecond engagement timescales are 2 orders of magnitude faster than the time of flight of a hypersonic missile! Therefore, a tactical hypersonic intercept could be possible, if the targeting loop can be closed fast enough, with the constraint that seconds to minutes long targeting timescales may limit effectiveness of missile intercepts at tactical ranges. DEW effects data on real or surrogate targets are required to solidify the assumptions about effectiveness timescales in these order of magnitude estimations. Experimentation to collect such data are underway, and should be continued as threats evolve. At longer ranges, for example intercontinental missile ranges, the time required to close the F2T2EA loop is longer, on the order of tens of minutes. Mid-course engagement from a pre-positioned DEW, space-based or high altitude, could therefore be effective on intercontinental ballistic missile timescales. For long to medium range cruise missiles today, which travel near Mach-5 over hundreds of kilometers distance, flight times are on the order of a few minutes. Finding, fixing, tracking, and targeting of missiles may also take minutes, necessitating a rapid engagement. Thus, a pre-positioned DEW, airborne or space-based, could be effective on fast enough timescales to permit mid-to-long range cruise missile intercepts. Ground or ship-based DEWs, for base-defense missions may also be effective if they can close the targeting loop fast enough. Future Trends for DEWs and Speed of Light Effects: Future trends in DEWs will be driven by military needs for high speed effects. This includes both for informational, counter-sensor, counter-material, and non-lethal effects, when rapid reaction times are not necessarily critical, and counter-air effects when they are. As analysis in this section demonstrated, at tactical engagement distances, closing the F2T2EA loop in less than a fraction of a second will be required to effectively counter tactical hypersonic missiles. An optimistic goal by 2060 would be to reduce targeting and engagement latencies for DEW systems, at tactical distances, to milliseconds for space, air, ground, and maritime based weapons performing counter-air-missions. Reduction to millisecond timescales could permit multiple DEW intercepts, which may be necessary in future conflict scenarios where multiple targets are likely. Longer range defense, where missile flight times may be minutes, do not require such short latencies. Unfortunately, at longer distances, DE beams suffer from divergence. Consequentially, longer distances require longer dwell times to create effects, and this argues for higher power/energy DE systems that can put sufficient energy on target to cause rapid effects. Still, in conservative and even pessimistic predictions, concepts of operations can be conceived that appropriately pre-position weapons in order to counter missiles. For pre-positioned weapon concepts, the technical challenges to resolve are reduction in SWAP and achieving affordable and reliable CONOPs. Pessimistically, the goal of reducing latency in targeting could be achieved by 2060, because in 2020, many of the foundational capabilities required for these types of missions are already proven. Electronics and computing, especially with anticipated advances in autonomy, are likely to quicken and be more efficient by 2060. Conservatively we expect that with advances in electronics and computing, targeting on millisecond timescales will be possible by 2060. These future trends in electronics and computing speed will be driven by both commercial and military needs. Optimistically, with advances in computing and higher-bandwidth electronics, microsecond or shorter timescales could be realized. Low-energy DEW effects can be achieved today with particle beams, HPEM, and lasers. Each of these technologies have SWAP challenges and some are power limited. For those reasons, although closing the targeting cycle is forecast to be conservatively achievable, an optimistic DE future is required for DEWs to be militarily relevant in tactical missile defense. The achievement of much higher energy solid state lasers is therefore an inflection point for DEW technology, enabling critical missions in 2060. Reduction of SWAP in particle beam and HPEM systems, such that airborne and space borne applications allow pre-positioned CONOPs, could be another inflection point. With the development of solid-state sources, HPEM SWAP reductions are expected, as was described in Sec. 2.2. SWAP reducing technologies were also described in Sec. 2.3, with regard to particle beams. Amplifying a concept discussed briefly in Sec. 2.2, for future information, counter-sensor, and counter-electronic applications of power within a battlespace, with all of the frequencies and wavelengths of DE discussed, it is an obvious conclusion that frequency agility is also an important concept. In fact this concept will be a vital enabler of information superiority operations by 2060, in order to operate in a contested and congested electromagnetic spectrum. Interestingly, the concept of frequency agility is also one of importance when considering the ability to engage multiple targets across the battlespace. One can predict that in the future, and perhaps even by 2060, the pace of battles may be measured on millisecond timescales, which by some estimates is faster than a human can think. Today the technology exists in research labs to conduct the DE version of a Rock’em Sock’em robot battle, where “Red” closed loop DE weapon and sensor systems battle “Blue” closed loop DE weapon and sensor systems. Both systems can autonomously and rapidly vary tactics, agilely switching frequencies, to create a variety of spectrally precise effects, all while defending against, and attempting to overcome each other’s attack. These simulated battles are waged at speeds on the order of milliseconds, enabled by autonomous sensing and decision making. Military utility of DEWs across a wide range of missions and platforms requires that they meet size, weight, and power requirements (SWAP) in addition to affordability and considerations of Doctrine, Organization, Training, Materiel, Leadership and education, Personnel, and Facilities (DOTMILPF). As has been described already, today DE finds use in several militarily relevant applications. Specific examples consist of DE illuminators and electromagnetic jammers widely accepted as essential components of both how the U.S., Allies, and near peer competitors apply military power across all phases of conflict today. These DE technologies are integrated into a variety of military platforms and have achieved acceptable SWAP characteristics. Technology trends over the next 40 years will continue to push directed energy weapon SWAP reduction in several ways. As with any military technology, adoption of DE technology remains likely if the technology can either accomplish a unique and necessary function that enables a mission, or if within the considerations of DOTMILPF, when compared with alternative approaches DE enables a more affordable solution. For this reason, today most discussions of cost of DEWs revolve around the ability to achieve the promise of a deep magazine and low cost per shot. Neglecting non-recurring engineering costs, for the systems of today, in 2020, we have achieved those balances in several areas. Pointers, jammers, dazzlers provide unique capabilities in affordable, SWAP acceptable packages. Mobile weapons for shooting down soft targets and denying ISR collection are already proving more effective than many alternatives (Michel 2019). Take for example counter-UAS capabilities; net guns, shotguns, are effective at 10s of meters ranges, but less effective than c-UAS DE systems at ranges nearing 1 kilometer. Missiles or UASs can achieve c-UAS effects at long ranges, but are expensive compared with the favorable cost per shot that c-UAS DE systems provide. Counter-UAS DEWs also provide the unique capability to defeat swarms in a single or few shots—achieving low-cost per shot and deep magazine effects. Given the state of DEWs today, we conservatively predict that DEWs will be able to achieve lower cost per shot and deeper magazine than alternatives for several specific missions by 2060. The ground and maritime base defense mission areas are already nearing that tipping point. Table 1: Summary of DE Missions & Military Utility in 2020 and conservative forecast in 2060: • Information Superiority: Effects: Deny, Degrade, Damage, Deceive; Platforms: Ground, Naval, Air, Space; Assessment: 4/5 stars. • Non-Lethal Effects: Effects: Deny, Degrade, Damage, Deceive; Platforms: Ground, Naval, Air, Space; Assessment: 4/5 stars. • Counter Electronic/Sensor: Effects: Deny, Degrade, Damage, Destroy, Deceive; Platforms: Ground, Naval, Air, Space; Assessment: 5/5 stars. • Counter Air: Effects: Deny, Degrade, Damage, Destroy, Deceive; Platforms: Ground, Naval, Air, Space; Assessment: 4/5 stars. Future Trends for DEWs in SWAP and Affordability: The commercial laser, communications, electronics, and semi-conductor industries have been technology drivers for the past 50 years, and we can expect that those industries will continue to drive trends toward smaller packaging and better electronic efficiency. These commercial forces will drive trends in SWAP and affordability more than military applications. While it is challenging to contemplate all of the myriad ways technologies will be different in 40 years, we can reliably predict that militaries will follow important technological trends that develop in the rest of the world’s biggest markets. The information sector of the U.S. economy, reliant on the current semiconductor architecture, in 2020 is expected by many to be a huge growth area and is closely monitored today (Lerman, et al. 2020). One could argue that the information and consumer electronics industries underlie most, if not all, of the other contributors to the U.S.’s GDP defined by world-leading economics analysts (The Deloitte Network 2019). Thus, technology drivers in electronics and communications will be primarily influenced by investments made by commercial industry, which is estimated to be in the trillions of dollars. The U.S. investment in all of military equipment and operations in 2020 is $740 Billion dollars, less than 1% of which is invested in electronics, communications, EW and DE research. We conservatively can expect therefore that the technological trends over the next 40 years in electronics, communications, EW, and DE will be driven by investments from the commercial sector. One can expect that commercial industry will drive toward specific goals for better power efficiency, more affordable, smaller, more integrated package sizes, and faster rates, driven by desires to decrease costs and raise profits. If these commercial drivers result in new technology architectures, DE technology will follow suit. The U.S. Military and its Allies should therefore invest in development of electronics and electro-optical systems to meet specialized needs that satisfy uniquely military requirements. For example, military applications often require higher power or higher energy devices. Hence, investments by militaries should focus on those aspects of electronic and photonic devices, while leveraging commercial and industrial technology trends in both electronics and photonics over the next 40 years to reduce SWAP and cost. Breakthroughs are also expected in several areas e.g. material, manufacturing, and component-level breakthroughs that can result in further reduction of system size and weight while increasing power output. Specifically, current research in solid state switches, batteries, and capacitors, key HPEM system components, will conservatively evolve and could lead to breakthroughs in HPEM effectiveness. Another potentially exciting development is in Gallium-nitride, a material dubbed “the next silicon” because it shows promise for replacing silicon, the current backbone of electronics (A. Chen 2019). It is reported that Gallium-nitride sustains higher voltages, conducts current faster, and more efficiently. These improvements all hint at significant SWAP, affordability, and efficiency improvements in all electronic devices in an optimistic future for DE. The futures states analysis that we performed is conducted in the context of DE 1.) Prevalence, 2.) Science and Technology advancements, and 3.) Military relevance/utility. The trends analysis assumes the three categories to be mutually independent. Global Prevalence captures who world-wide is projected to utilize DE for military applications: Pessimistically, the U.S. and Allies do not have access to the most effective DE technology, while unfortunately others do; Conservatively the U.S., Allies, peer-competitors, rogue states, terrorist and criminal organizations have access to DEWs, as is the case today in 2020; Optimistically the U.S. and Allies only would have access to the most effective DE technology in 2060. Definitions of the S&T Advancement category are: Pessimistically, DEWs are no more advanced than they are today; Conservatively, incremental continuous improvement in DE tech will progress towards goals stated in Sec. 2; Optimistically, either by incremental engineering advancement or tech breakthroughs, the stated tech goals will be achieved. Military utility/relevance in 2060, pessimistically, will be roughly the same as today, niche applications and useful for informational and counter-informational operations; Conservatively, DE-enabled missions will grow; Optimistically, DEWs will be of great military utility because they enable important missions that could not otherwise be accomplished, and/or DE technology significantly reduces cost and/or complexity over alternative approaches in 2060. Given the background and stated pessimistic, conservative, and optimistic trends in DE discussed in Sec. 2, we now describe seven future states: 1. Positive DE US futures: a. Big Dog – Prevalence: Optimistic / S&T: Optimistic / Relevance: Optimistic - Summary description: Major advances are made across DE enabling technologies and translate into military capabilities that have a major impact on military operations across the kill chain, within and across domains and across all phases of conflict. Within this future the US & Allies maintain a significant lead over all rivals and potential adversaries in DE enabling technologies, and in converting those technologies into required military, operational capabilities. - Challenges: With such a high level of military significance for DE enabled capabilities peer competitors vigorously pursue matching if not exceeding US DE capabilities. The U.S. is hard pressed to maintain a technological lead across the wide area of DE technologies and capabilities relevant to military applications. Any such lead remains intrinsically fragile in time and as to military advantage. b. DE niche world - Prevalence: Optimistic / S&T: Pessimistic / Relevance: Optimistic - Summary Description: Only moderate progress in advancing DE technology is achieved, but that sufficiently produces significant areas of important military capabilities. These military capabilities have specific applications within the kill chain, across domains and phases of conflict. The U.S. retains a significant advantage in S&T and in operational capabilities in niche areas over rivals and adversaries. - Challenges: The U.S. advantage in S&T and operational capabilities is continually challenged by U.S. rivals and potential adversaries. The advantage is difficult to maintain in a flatter technical and economic world of accelerating technological change. The U.S. must guard against technological surprise across the broad areas of potential DE military application. c. Prevalence: Optimistic / S&T: Optimistic / Relevance: Pessimistic This future can manifest in two states: - Triumph of counter-DE: Nations make great progress broadly across DE technologies, but technological progress enabling DE offensive and defensive application are outstripped by technologies defending or defeating such applications. Although only the U.S. and its allies have DE capabilities, counter-DE capabilities proliferate widely among the U.S.’s rivals and potential adversaries. The principal military value of DE lies in providing information services to drive the kill chain. Challenges: In this future there is parity between counter-DE offensive and defensive applications and in the defense of DE information capabilities against attack. There is an on-going “arms race” between DE defense and DE offensive/defensive applications. - Pacifist Utopia: Great progress is made in DE S&T but there is world-wide consensus against its military application akin to restriction on tactical use of nuclear weapons. As such, advances in DE S&T and capabilities are limited to scientific and commercial applications or information dominance military applications. Challenges: With technologically capable DEWs the U.S. and its Allies still remain at risk from non-state actors who are unconstrained by international agreements. 2. Competitive DE US Futures: a. Crowded DE battle-field - Prevalence: Conservative / S&T: Conservative / Relevance: Conservative - Summary Description: In this future a broad spectrum of actors achieves significant and sweeping advances in DE technology: the U.S., Allies, rivals, and potential adversaries. The U.S. maintains parity in DE technology and in its military applications for information dominance and offensive and defensive operations. Significant military applications apply to the kill chain, across domains and across the phases of conflict. - Challenges: This is a highly multi-polar DE future. In an economically and technologically flatter world, the U.S. is continually challenged militarily to maintain parity in DE technology and operational applications. An ongoing DE “arms race” exists based on the common recognition by the U.S., its rivals and potential adversaries of the significant military advantage that superiority in DE military capabilities can provide. b. Failed Promise - Prevalence: Pessimistic / S&T: Pessimistic / Relevance: Pessimistic - Summary Description: This is a future of only modest advances in DE science and technology and only modest increases in DE military capabilities. While DE has military applications, they tend to be niche applications with limited importance across the kill chain, across domains and across the phases of conflict. Despite an overall lack of technological progress and military utility the U.S. is not a leader in DE technology or in DE military applications. - Challenges: In this future the U.S. becomes disadvantaged compared to its rivals and potential adversaries in developing and deploying DE military capabilities. 3. Negative DE US futures: a. Missed Boat/Odd Man Out - Prevalence: Pessimistic / S&T: Optimistic / Relevance: Optimistic - Summary Description: This is the worst-case DE future for the U.S. In this future, major advances occur across a plethora of DE S&T, and are converted into important military capabilities by a number of U.S.’s rivals and potential adversaries across the kill chain, domains and phases of conflict. The U.S. lags these rivals and potential adversaries. This is the result either of a conscious U.S. decision to invest in other areas that provide equivalent or superior military capabilities or a failure to predict the military utility of DE and invest in the S&T and the development of DE capabilities. - Challenges: Unless other technologies pursued have produced offsetting or superior military capabilities, in this future the U.S. sits at significant, military disadvantage compared to its rival and potential adversaries. In a technologically and economically flat world, catching up is highly difficult. Predictions of the future are fraught with peril; one could be wrong. Still it is worthwhile to organize thoughts around a vision for the next 40 years. Furthermore, the military must function to protect and defend which requires planning for future conflicts. It is not a certainty that U.S. servicemen and women will be members of the most technologically sophisticated military in future conflicts. DEWs are currently being rapidly developed and proliferated around the world, and DE is globally considered to be a game-changing military technology. The impact DEW technologies will actually have over the next 40 years is still to be seen. This report only seeks to organize thoughts around a realistic vision for DEW technologies in 2060. Data gathered for this report shows that both in the past, today, and likely into the future, 2060, DEW proliferation will be driven by the requirements for three capabilities which will be needed to face enduring challenges: • Information superiority operations that promise control of the electromagnetic spectrum. Electromagnetic spectrum superiority in a conflict requires EW or DE weaponry. • Capability to project military power faster, at longer stand-off ranges, and efficiently, as part of an integrated layered defense which includes command and control, ISR, cyber, and kinetic weapons. • Unique, intermediate force, special operations, and potentially space-based missions that require flexibility, scalability, and precision effects across all domains and phases of conflict. Today, we believe that we retain at least parity with peer-competitors. Low-power DE technology is currently available to anyone, world-wide, with means to buy it: the U.S. and Allies, peer-competitors, rogue nations, criminal organizations and terrorists. In the most probable future, the U.S. and Allies will continue to play a major role in the advancement of DE for military purposes. Fortunately, today the U.S. has close collaborations with Allied DE scientists, developers, military operators, and strategists. We plan to continue to partner internationally with our Allies in DE development, further strengthening our collective military power and investment. Unfortunately, in the most probable future from a proliferation perspective, the U.S. and Allies will not be the only ones who wield DEWs. The key question is, to what degree peer-competitors, rogue nations, terrorists, and criminal organizations will possess competitive DE capabilities? Over the next 40 years, we predict that even in a pessimistic case, the technology barriers for development of high-energy, high-power, operationalized DEWs will be steep, and investment in DE is the key to the U.S. and Allies retaining leadership in these tech areas. Regrettably, historical trends have shown that with significant investment and technical knowledge, DEWs can be created or purchased by any organization world-wide, and therefore policies must be developed to maximize our ability to access technical talent and the most advanced equipment: electronics, sensors, optical and RF components, and DE-unique materials, some of which require advanced manufacturing. A lesson that one must cautiously observe from the Cold War is that technological and military investment can drive national costs to unacceptable levels, and as threats to national power continue to evolve over the next 40 years, there must be continued assessment of DE’s value. Recommendations: • The U.S. should choose appropriate investments that will maintain electromagnetic spectrum and information superiority. DE and EW are a key technologies in that regard. From laser illumination, designation, laser and RF tracking, communications, jamming, and counter-ISR, DE devices are key to future information superiority. Continued investment is needed to establish spectrum superiority in future conflicts, across a variety of intensities and frequencies in the electromagnetic spectrum and with advanced concepts such as frequency agility. • The U.S. and Allies should continue to develop concepts for information operations that use electromagnetic spectrum superiority to create asymmetric advantages. • The U.S. DE community should request revision of Joint Doctrine Publication 3-13 to include DE as an offensive and defensive information operational capability. In Joint Doctrine Publications 3-85, the distinctions between DE and EW should be clarified, and eliminated where redundant, in order to align the joint services behind concepts of operation. • The U.S. and Allies should continue to investigate and discover new applications of DE technology. Investments should be made in areas where missions make sense: such as information operations, high-altitude long-range strike, tactical forward strike missions, and tactical air, space, ground, and ship-based defense missions. • For self-protection, such as aircraft, naval, and base defense, where today research into DE systems have fundamental speed, efficiency, and potentially cost advantages over traditional kinetic technologies, to include counter-ISR and counter-electronic attack today; research and development is needed to continually improve high-power/energy DE technology lethality and effects research, as the Allied DE community strives for counter-air technology of the future. • For the national defense, the “holy grail” mission is a nuclear and/or conventional missile umbrella employing a layered defense concept that includes traditional weapons, DEWs, advanced C4ISR. This mission is increasingly important as concepts for swarms of UASs gain traction and missile technologies advance. Speed, reach, and low-cost per shot are advantages in point defenses that DEWs have demonstrated today; the DE community should strive for both more effective DEWs that realize the benefits of rapid engagement, and concepts of operations that address operational challenges in an affordable architecture. • Focusing on proliferation and military utility, even in a pessimistic technological future, furtherance of today’s non-lethal and non-kinetic kill intermediate force capabilities will continue. Moreover, it is anticipated that peer-competitors, rogue nations, terrorist and criminal organizations will continue to possess similar DEWs that can degrade, disrupt, deny, damage, and even destroy equipment. Therefore, the U.S. should invest in technologies to at least maintain parity in DE areas, which includes counter measures to shore up known vulnerabilities in case of either a high-end conflict or a 9/11, terrorist style, DE attack. • Driven by trillion-dollar commercial forces— the aerospace, information, and consumer electronics industries— electronics and photonics will continue to advance during the next 40 years. The DE community should leverage these industries, and reap the benefits of that external investment to overcome many of the engineering challenges in the areas of affordability and SWAP. • In addition to leveraging advancements by others, the U.S. and Allied militaries should continue investment in areas where DE technology is driven by militarily unique requirements, several of which are discussed throughout this document. • The U.S. and Allied militaries should continually evaluate what technologies to limit for classification purposes, exportation controls, and supply chain issues. We plan to study this problem in more depth, to supply specific details to policy makers in future U.S. DE Community of Interest reports. • The U.S. and Allied nations should continue to invest in education, facilities, and institutions in order to retain DE leadership. Appendix A: Future States Vignettes Vignette 1: DE defends resources in space (12-14 September 2060) Describes a fictional scenario set in Mars orbit and the asteroid belt involving commercial asteroid mining conglomerates (Chinese state-sponsored Abundant Harvest Asteroid Corporation vs. U.S.-backed Deep Space Resources). Tensions escalate when Chinese vessel Vessel 20 ejects mining debris towards the U.S. craft. In response, Commander General Alighieri utilizes Mars-orbiting defensive laser weapons (a 2 Gigawatt beam-combined system and an ultrashort femtosecond pulse laser) to surgically breach the airlock of Vessel 20 as a proportional response without human casualties. Analysis: Highlights optimistic DE technology advancement and U.S. dominance in high-energy space-based lasers (Big Dog scenario). Vignette 2: Ultra-small particle device disables C2 systems (15-17 March 2060) Describes an engagement along the Sino-Indian Himalayan border where PLA drone incursions are repulsed when the Indian military activates a clandestine, ultra-small particle beam device embedded on the circuit board of Chinese TigerStar network switches inside the PLA's mountain command bunker. The microscopic device induces molecular-level hardware destruction, knocking out communications and halting the offensive. Analysis: Illustrates conservative S&T advances in compact particle beam sources applied in special operations and covert hardware sabotage (Crowded DE Battlespace / DE Niche World). Vignette 3: Failure to defend homeland against advanced missile strikes (1-2 February 2060) Fictional scenario recounting the assassination of U.S. President Blumm and Secretary of Defense Leo Steinbeck in a hypersonic strike on the 'Hexagon' command center by Russian Free Armed Forces (RFAF) using Mach 10+ CODA-engine missiles. U.S. defenses fail because legacy interceptors and short-range DE systems lacked the speed, forward-basing, and autonomous engagement loops necessary to intercept hypersonic threats within seconds. Analysis: Illustrates the dangers of falling behind in technology and having an inadequate DE architecture against high-speed threats (Missed Boat scenario). Appendix B: Participating Organizations • Air Force Materiel Command • Air Force Office of Scientific Research • Air Force Research Lab (Co-Host) • Air Force Space Command • Army Space and Missile Defense Command • Defense Health Agency • Directed Energy Professionals Society • Joint Non-Lethal Weapons Directorate • Joint Directed Energy Transition Office • Los Alamos National Lab • Lawrence Livermore National Lab • Naval Research Lab • North Atlantic Treaty Organization (NATO) • Office of Naval Research • Office of Secretary of Defense - Directed Energy Community of Interest (Host) • Office of Undersecretary for Defense – Research & Engineering • Pennsylvania State University • Purdue University • Sandia National Lab • The Aerospace Corporation • The MITRE Corporation • The Leonardo Company • United States Space Force • University of New Mexico • University of Missouri Appendix C: 2060 Assumptions Economic Assumptions: • A tripling to quadrupling of global GDP with an annual average growth rate of 3%-4% over the period to 2060. • U.S. economy doubling with an annual average growth rate of 2% over the period to 2060. • U.S. portion of global GDP decreases from current 22% to between 10% and 15%. • Large, developed economies experience similar or lower growth rates relative to the U.S. • Chinese and Indian economies significantly exceed U.S. in size but lag in per capita GDP. • World population increases 30% to near 10 billion, primarily in developing nations. • Top economies are China, India, United States, Indonesia, Brazil, Russia, Mexico, Japan, Germany, and the United Kingdom. • Global economy is more integrated and driven by automation, artificial intelligence, robotics, and additive manufacturing. • The growing economy increases demand and competition for natural resources. Political Assumptions: • Global political power is distributed across a wide range of nations driven by increases in overall global wealth and a more evenly distributed technical base and world economy. • U.S. remains a first-tier power, but with its political power diminished relative to other first-tier nations. • Tiering of nations by level of power continues with narrowed differences between and within tiers. • Europe and North America continue to control a disproportionate percentage of global power relative to their populations. • U.S. is not the preeminent world power by multiple measures. • Wider distribution of power increases potential for competition and conflict. • Premium on flexible partnerships and alliances to support shifting national needs, priorities, and changing geopolitical balance. National Defense Assumptions: • The continuation of great power competition. • A highly multi-polar world with a significant number of nations and alliances having equivalent economic power and technical infrastructure but diverse and divergent interests. • Conflicts increasingly integrated across the air, land, sea, cyber, and space domains and extending globally and across cislunar space. • The cyber domain is critical to military operations. Foreign competitors increasingly seek cyber capabilities to target systems and infrastructure. • Conflicts occur at greater speeds and range across an ever increasingly diverse set of integrated and flexible platforms and systems. • Technical advantages between major powers has narrowed or disappeared. • Success is driven more by resources, logistics, and successful alliances rather than by technological advantage. • There may be a wide range of conflicts involving a wider set of countries with significant military power. • Increased global competition leads to an increased number of conflicts. Appendix D: Acronym List • AI: Artificial Intelligence • C2: Command and control • C4ISR: Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance • c-UAS: Counter Unmanned Aircraft System • CEP: Probable Circular Error • CONOPs: Concept of Operations • DE: Directed Energy • DEW: Directed Energy Weapon • DoD: Department of Defense • DOTMILPF: Doctrine, Organization, Training, Materiel, Leadership and Education, Personnel, Facilities • EW: Electronic Warfare • HPM: High Power Microwaves • HPEM: High Power Electromagnetics • GDP: Gross Domestic Product • JADC2: Joint All Domain Command and Control • LASER: Light Amplification by Stimulated Emission Radiation • OSD: Office of Secretary of Defense • NASA: National Aeronautics and Space Administration • NATO: North Atlantic Treaty Organization • NDPP: NATO Defense Planning Process • S&T: Science and Technology • SI: The international system of units • SWAP: Size, Weight, and Power • TRL: Technical Readiness Level • U.S.: United States of America • UAS: Unmanned Aircraft System Appendix E: Description of Units of Measurement • Energy of a photon in Joules (J) is proportional to frequency in Hertz (Hz), h = 6.626 x 10^-34 J·s. • Power is measured in Watts (W = J/s). • Prefixes: femto (f) = 10^-15; pico (p) = 10^-12; nano (n) = 10^-9; micro (μ) = 10^-6; milli (m) = 10^-3; base unit = 1; Kilo (k) = 10^3; Mega (M) = 10^6; Giga (G) = 10^9.