War at the Speed of Light: Directed-Energy Weapons and the Future of Twenty-First Century Warfare. Louis A. Del Monte. Lincoln, NE: Potomac Books, 2021.
The character and conduct of warfare are inextricably linked to the evolution of technology. Warfare is a driver of technological innovation, and innovation itself changes how wars are fought in often unforeseen and unpredictable ways. The pace of technological change is accelerating and, at the same time, the impact of those same changes is exponentially growing—a sort of Moore’s Law for warfare.
Louis A. Del Monte’s latest book, War at the Speed of Light: Directed-Energy Weapons and the Future of Twenty-First Century Warfare, explores how lasers, electromagnetic weapons, and other energy-based or energy-driven weapons could change how future wars are fought. Del Monte argues these technologies will accelerate the pace of war. The use of directed-energy weapons will mean a faster time to kill resulting in smaller windows for decision making at all levels of conflict. Taken together with artificial intelligence and cyber weapons, Del Monte argues these changes will upend strategic stability as we understand it today.
The book’s setup, structure, and premise are well-suited to this fascinating subject, and Del Monte’s approach and argument have a natural logic and flow. Over the course of twelve chapters, divided into four parts, Del Monte explores the evolution of directed-energy weapons and their implications. In the first quarter of the book, Del Monte establishes a framework for understanding the development of the balance of terror of mutually assured destruction with the Soviet Union, how countries sought conventional primacy amidst this arms race, and the emergence of the fourth offset strategy and what it means for the future.
This structure is a solid foundation from which to assess the implications of directed-energy weapons. Understanding where we came from is necessary to understand where we will go in the future, particularly with the advent of weapons that could well close the kill chain nearly instantaneously.
The next four chapters explore laser weapons, microwave weapons, electromagnetic pulse devices, and cyberspace weapons, discussing the development of each and how they could be implemented on a future battlefield. Some of these weapons are already in development, some are prototyped, and others remain on the drawing board at the moment. As Del Monte notes, the U. S. is not alone in pursuing these weapons—America’s strategic competitors in Russia and China are aggressively investing in research and development across the directed-energy spectrum.
Del Monte then briefly addresses potential countermeasures to include force fields—which sound like something straight out of science fiction, but are rapidly becoming anything but. He closes with a three-chapter exploration of what the preceding developments mean for warfare that first discusses the implications of the confluence of artificial intelligence and directed-energy weapons. He then explores what this means for potential conflict in the newest warfighting domain, space. Having established what the nexus of these technologies looks like in practice, he offers a warning about what these developments collectively mean. This final section brings Del Monte’s arguments full circle, exploring from where we came, to where we are, to where we could well go with, as the title implies, war at the speed of light.
The key shortcoming of Del Monte’s book is that it is missing a necessary depth of analysis to support his assertions. As it stands, Del Monte makes a strong claim, but does not stress test the argument by looking at it from alternative points of view. For example, he is not wrong to suggest that artificial intelligence and autonomous weapons systems will change the speed of engagement and time to kill. However, there are a number of significant technological, budgetary, and policy hurdles that must be overcome before that scenario comes true. These are hurdles that Del Monte, unfortunately, does not fully explore.
For Del Monte, that the technology will find itself on the battlefield in the very near future is a fait accompli, but he offers this assertion without sufficient grounding or critical assessment. In the section on lasers, for example, the author references those deployed on the USS Ponce and later the USS Portland, but they have neither been widely fielded nor had a demonstrable effect in an engagement or contested environment. The closest real-world application of this technology was the use of the Light Marine Air Defense Integrated System, or LMADIS, against an Iranian drone in July 2019. In practice this, however, appears to be a traditional, albeit modernized, electronic warfare tool, as opposed to a directed-energy weapon. Indeed, the U.S. now seems to be rediscovering the broad spectrum of electronic warfare capabilities, beyond the narrow band of counter-improvised explosive devices tools.
War at the Speed of Light is also missing a critical reflection on the state of American defense innovation and investment in these weapons systems. Del Monte does describe some of the programs, but does not offer a cost-benefit analysis or breakdown. He simply assumes investment will be made in these capabilities. In the U.S. Navy’s 2022 budget request, two key line items related to rail gun research and development are zeroed out. While this book was published several months before the budget request’s release, it illustrates the volatility of funding prioritization nonetheless, a consideration crucially omitted from Del Monte’s presentation. “No bucks, no Buck Rogers,” as the phrase goes.
The fixation on technology is also divorced from geopolitical strategic considerations. Weapons are merely tools in the hands of states, and it is not a foregone conclusion that just because something is novel that a state will use it. For example, he rightly notes electromagnetic pulse weapons are a potential threat, but he does not ask whether Russia, China, Iran, or North Korea would risk almost certain nuclear retaliation in response to such an attack on the United States. Equally, given recent developments it would seem much more likely that a deniable cyber-attack is more attractive.
Del Monte breezily slides from the strategic to the tactical levels and often confuses tactical utility with strategic effects. True, a laser weapon could well be used to disrupt swarms of drones and possible cruise missiles, but so too can the Close-In Weapons System. That effectiveness has not yet translated into utility against intercontinental ballistic missiles (ICBMs) and may never do so. For all of the investment and testing of the Airborne Laser Testbed (YAL-1), the program was still cancelled in 2011 and the aircraft mothballed in 2012.
Another challenge is that many of these subjects have been addressed in much greater depth, with a much more critical eye, elsewhere. George Beebe, in his book Russia Trap, looks at the risk of cyber warfare undermining mutually assured destruction with Moscow. Nicole Perlroth’s This is How They Tell Me the World Ends explores the cyber arms race for zero-day exploits and the resulting risks of cyberwar. Chris Brose succinctly breaks down the risks of under-innovation and under-investment in key technologies as it applies to strategic competition with China in his book The Kill Chain. Sir Lawrence Freedman explores how forecasting the future of warfare and the tools with which it will be fought is rife with failure in his book The Future of War. These are all books within arms’ reach from my desk that address elements of Del Monte’s arguments better and more succinctly.
Technological fetishization also misses the reality on-the-ground. For all the changes in modern warfare with the application of drones, loitering munitions, precision fire support, cyber weapons, and more, many things remain the same. Trenches are still used in Donbass. Barrel bombs and improvised munitions are used in Syria. Comparably low-tech anti-tank guided missiles are found on the battlefields of Yemen. This is to say nothing of the fact that for all the investment Moscow made in its modernization program, it still chose to use little green men, propaganda, and covert action, with a dash of cyber weapons to annex Crimea and destabilize Ukraine. In reality and in war, the more things change, the more things stay the same.
This article appeared originally at Strategy Bridge.
 Moore’s Law posits that computing power would increase and the price for that computing power would decrease at an exponential rate.
 Offset strategies are evolutions of America’s defense posture to change disadvantageous strategic positions primarily via emergent technology.
 Megan Eckstein, “USS Portland Fires Laser Weapon, Downs Drone in First At-Sea Test,” USNI News, May 22, 2020, https://news.usni.org/2020/05/22/video-uss-portland-fires-laser-weapon-downs-drone-in-first-at-sea-test
 Andrew Liptak “A US Navy ship used a new drone-defense system to take down an Iranian drone,” The Verge, July 21, 2019, https://www.theverge.com/2019/7/21/20700670/us-marines-mrzr-lmadis-iran-drone-shoot-down-energy-weapon-uss-boxer
 Joseph Trevithick, “The Navy’s New Railgun Looks Like It’s Finally Facing the Axe in New Budget Request,” The Drive, June 1, 2021, https://www.thedrive.com/the-war-zone/40875/the-navys-railgun-looks-like-its-finally-facing-the-axe-in-new-budget-request
 The Right Stuff, directed by Philip Kaufman (Warner Brothers, 1983).
 Tom Z. Collina & Kelsey Davenport, “Airborne Laser Mothballed,” Arms Control Today, March 2012, https://www.armscontrol.org/act/2012_03/Airborne_Laser_Mothballed