The Kill Chain

Christian Brose spent more than a decade watching the United States military lose future wars on paper. As staff director of the Senate Armed Services Committee under the late Senator John McCain, and before that as his senior policy adviser, Brose sat in on the classified briefings, the war games, the budget hearings and the quiet corridor conversations in which America’s defence establishment began to admit, around the middle of the last decade, that something had gone badly wrong. The Kill Chain, published by Hachette in April 2020, is his attempt to drag that admission out of the vault and into public argument. The book arrived two years after McCain’s death, as Brose was moving into the private sector as chief strategy officer at the defence software firm Anduril, and it sits inside the broader shift embodied by the 2018 National Defense Strategy — the pivot away from two decades of counter-insurgency in the Middle East toward what the Pentagon now calls great-power competition with China and Russia. The field Brose was joining was already crowded with think-tank papers and classified studies warning that the American military was becoming a hollow, expensive instrument. His contribution was to translate that insider pessimism into plain prose and to pin the diagnosis on a single idea: the kill chain.

The kill chain, in Brose’s telling, is the sequence by which a military senses the world, decides what to do about what it has seen, and then acts on that decision. In doctrinal language it has long been broken into stages — find, fix, track, target, engage, assess — but Brose uses the term more generally to mean the loop of understanding and action that any armed force must close to be useful. His argument is that the United States spent the three decades after the 1991 Gulf War perfecting the striking end of that chain, buying beautifully precise munitions and the platforms to deliver them, while assuming that the sensing, deciding and connecting parts of the loop would remain uncontested. China, he argues, built the opposite military. Rather than try to match American aircraft carriers and strike aircraft, Beijing designed its forces specifically to break the American kill chain — to blind the satellites, jam the data links, hunt the carriers, flood the airspace with cheaper missiles than the United States can defensively intercept, and target the handful of large bases on which forward American power depends. The result, he writes, is that in classified war games the United States has been losing to China for years, not because its weapons are inferior one by one but because the chain that connects them cannot be closed under contested conditions. The military the country owns, he argues, is the wrong one for the war it is likely to face.

The book moves in a widening arc from that opening alarm. The first chapters set the scene with scenes Brose personally witnessed — McCain’s weary hearings, a 2015 moment when the then-deputy secretary of defence Robert Work turned to colleagues after a losing simulation and asked how American forces could possibly expect to prevail, the quiet revelation that American aircraft had already lost the open skies the service had taken for granted since Vietnam. He then turns to how the country arrived at this point, tracing a procurement culture that rewards very large, very long programmes designed around assumptions a generation old. He treats the Ford-class aircraft carrier, the F-35 Joint Strike Fighter, the Zumwalt destroyer and the Littoral Combat Ship as case studies in how a system optimised for industrial scale and congressional geography produces exquisite platforms the force cannot afford in numbers and cannot replace when lost. The middle of the book pivots to China and, more briefly, Russia, laying out how Beijing’s People’s Liberation Army reorganised itself around the explicit mission of denying American freedom of action in the Western Pacific — the family of anti-access, area-denial capabilities Western analysts have come to label A2/AD, built around the DF-21D and DF-26 anti-ship ballistic missiles, extensive cyber and space weapons, and a doctrine of system destruction warfare that targets the networks before the shooters. Russia’s work in Crimea and eastern Ukraine serves as a shorter case: a demonstration that even a weaker power can combine electronic warfare, drones, deception and precision fires to confound a conventional opponent.

Having described the problem, Brose turns to what he believes a working American military of the next decade should look like. His picture draws heavily on the Third Offset Strategy that Robert Work and Ash Carter promoted in the Obama Pentagon, on the Defense Innovation Unit’s early efforts to pull Silicon Valley into the department, and on the ideas circulating around Project Maven, the artificial-intelligence programme that applied computer vision to drone video and provoked Google’s internal revolt in 2018. He argues that the future force should be dispersed rather than concentrated; built from large numbers of smaller, cheaper, often unmanned platforms rather than a few irreplaceable ones; autonomous in meaningful ways so that machines rather than people are the limit on how fast the kill chain can close; and above all networked, so that a sensor on any platform can cue a shooter on any other. He uses the term “military internet of things” with some reluctance but defends the underlying picture. The decision to engage must still rest with a human, in his view, but the loops of sensing, correlating, cueing and effects assessment can and should be handed to software. Without that handover, he argues, no amount of courage or training will let American forces act faster than a Chinese adversary that has already automated its own loops.

The concrete material of the book is where its argument lives. Brose names specific systems and specific sums. He describes the Ford-class carrier as a thirteen-billion-dollar platform whose electromagnetic catapults were still breaking down years after commissioning, and places it alongside the two-billion-dollar-apiece B-2 and the F-35 as emblems of a bet on a very small number of very expensive nodes. He contrasts them with the attritable autonomous platforms being prototyped at the time — the Boeing MQ-25 Stingray carrier-launched tanker drone, the Kratos XQ-58 Valkyrie loyal-wingman concept, the Sea Hunter autonomous surface vessel — and with commercial-grade systems that cost in the thousands rather than the billions. He walks through the Chinese rocket force in enough detail to show how a dense volley of medium-range ballistic missiles can keep large aircraft out of fighting range of the first island chain, and through China’s investment in space and counter-space to show how the GPS, satellite communications and overhead reconnaissance on which the American way of war depends have become targets rather than givens. He writes about the Second Artillery’s reorganisation, about electromagnetic pulse concepts, about undersea cables, about the DF-17 hypersonic glide vehicle, about Chinese military fusion with its commercial AI champions. He draws on war games run at RAND and inside the services whose consistent finding, through the latter half of the 2010s, was that American forces fighting over Taiwan would exhaust their precision munitions in days and lose a large fraction of their forward-deployed aircraft and surface ships in the opening phase. He returns repeatedly to the people around McCain who tried to warn the system — Work, Carter, Elbridge Colby, Michèle Flournoy, Jim Mattis in his short tenure as defence secretary — and to the structural reasons their warnings produced incremental budgets rather than fundamental reform. His account of why Congress funds what it funds, and why defence contractors optimise for programmes that cannot be cancelled rather than products that can be fielded in numbers, is unsparing and drawn from personal experience.

The reception of The Kill Chain mapped closely onto the fault lines Brose himself describes. Among the defence intellectuals who had been making similar arguments inside the building, the book was treated as a useful public packaging of what they had been saying in classified rooms. H. R. McMaster, Mark Esper, Patrick Shanahan and others publicly endorsed its diagnosis of great-power vulnerability. Elbridge Colby’s own 2021 book, The Strategy of Denial, picked up the Pacific thread with a more pointed focus on Taiwan. Paul Scharre’s work on autonomy, especially Army of None and the later Four Battlegrounds, treats many of the same questions from a longer and more ethically focused angle. The pushback came along several axes. Service traditionalists argued that Brose underestimated the enduring utility of forward presence, that aircraft carriers survive precisely because they move and because an opponent cannot afford to miss, and that the problem with American procurement is not the preference for large platforms but the political impossibility of killing failing programmes. Arms-control and ethics scholars worried that Brose’s rhetoric about speed and automation, however carefully hedged, would be read inside the Pentagon as licence to delegate lethal decisions to software; the subsequent debate over fully autonomous weapons has borne this concern out. Analysts of Russia’s war in Ukraine, which began a full-scale phase almost two years after the book appeared, pointed out that the actual experience of modern high-intensity warfare looks less like a sudden decapitation and more like a grinding attritional contest in which drones, electronic warfare, artillery and logistics matter at least as much as the kill chains Brose foregrounds. In the policy world, however, the direction of travel after 2020 moved in the directions he had argued for. The Joint All-Domain Command and Control initiative, the Replicator programme announced in 2023 to field thousands of attritable autonomous systems within two years, the growing procurement weight given to small drones and loyal wingmen, and the willingness of the Pentagon to buy from non-traditional vendors like Anduril, Shield AI and Saronic are all consonant with the book’s prescriptions. Whether that is because Brose was right or because he was describing a current already running is a question the next decade will answer.

For a reader working through the literature on AI in warfare, The Kill Chain occupies a particular slot. It is the most readable Washington-insider account of why the American military is where it is, written by someone who was in the room during the pivot and who has a clear thesis rather than a balanced overview. It pairs naturally with Paul Scharre’s work for the longer view on autonomy and ethics, with Elsa Kania’s writing at CNAS for a more granular picture of Chinese military-civil fusion and the PLA’s own thinking about intelligentised warfare, with Michèle Flournoy’s essays and the Reagan Institute’s annual survey for the Washington policy perspective, and with Franz-Stefan Gady’s and Michael Kofman’s reporting on the actual Ukrainian battlefield for a corrective dose of what high-intensity war looks like in practice. It does not try to be a technical primer on machine learning, and it does not spend much time on nuclear issues, on allies and coalitions beyond a sketch of the Pacific partners, or on the European theatre. Readers interested in how the alliance structure might fight in Europe, or how continental militaries are responding to the same pressures, will need to look elsewhere. The book is also unmistakably a work of American political argument. Its tacit audience is a Congress and a Pentagon that could choose otherwise, and its tone of controlled impatience derives from years of watching them not.

Some of what Brose argued will age better than other parts. The core framing — that the real competition is over the ability to close the loop faster than the opponent, and that the United States spent too much of the past three decades buying platforms rather than chains — is more obviously correct in late 2026 than it was in 2020. The war in Ukraine has made the case for mass, attritability and software-defined systems more vividly than any think-tank paper could, and the drone-dense frontline there has given concrete form to the picture Brose sketched. Taiwan has only grown more central to American strategic planning, and the specific vulnerabilities he described — a handful of large forward bases, an airwing dependent on uncontested tankers, a surface fleet exposed to Chinese anti-ship missiles — have become the planning assumptions rather than the heresies. Where the book is already dated is in the specifics of which prototypes it treats as the vanguard; some of the programmes it names have faltered or been superseded, and the AI landscape in particular has moved so fast since 2020 that any book-length treatment of it from that year reads as a snapshot of an earlier era. The deeper argument about procurement culture, about the political economy of the defence industrial base and about the difficulty of making a very large bureaucracy change its mind in time has not aged at all. That is why the book is still being argued about in Pacific Command, in European defence ministries newly alive to the drone war on their doorstep, and in the venture-funded firms now trying to build the kill chains Brose said the country would need. Whether the warning was heeded in time is still an open question. The Kill Chain is the book that made the question hard to avoid.