A leaked US Department of Defense (DoD) assessment known as the “Overmatch” brief warns that the US would likely lose a high-end war with China over Taiwan under current conditions.
The classified, multiyear report, obtained by the New York Times (NYT), was prepared by the DoD’s Office of Net Assessment and delivered to senior White House officials over several years.
It maps how a conflict would unfold and concludes that China now possesses the means to destroy US aircraft, large naval vessels and satellites early in a fight, while exploiting critical US supply-chain vulnerabilities.
The brief details how China’s growing missile forces, low-cost drones and cyber capabilities could overwhelm US reliance on expensive, vulnerable platforms such as aircraft carriers and advanced fighter jets, leaving US forces unable to sustain a prolonged war.
According to officials cited by the New York Times, DoD war games consistently show US defeat, with one former senior national security official describing the assessment as revealing Chinese “redundancy after redundancy” against US advantages.
The findings underscore a broader warning that decades of investment in bespoke, slow-to-produce weapons, combined with eroded industrial capacity and limited munitions stockpiles, have left the US military ill-prepared for a conflict with a peer adversary, even as China accelerates its military preparations, including for a potential move against Taiwan by 2027.
Highlighting the shrinking military-industrial gap between the US and China, Seth Jones and Alexander Palmer state in a March 2024 report for the Center for Strategic and International Studies (CSIS) think tank that China has put its defense industry on a wartime footing, leveraged military-civil fusion (MCF) strategy and effectively utilized massive shipbuilding, missile and munitions production capacity.
Jones and Palmer say that China now produces weapons systems five to six times faster than the US in key areas, such as missile and combat aircraft production, and has a shipbuilding capacity 230 times that of the US.
By contrast, they point out that the US defense industrial base has atrophied after decades on a peacetime footing, suffering from limited surge capacity, munitions shortfalls, fragile supply chains, workforce shortages, bureaucratic delays and inconsistent demand signals, undermining deterrence in a prolonged great-power conflict.
Focusing on China’s near-constant reveals of new military technology, Timothy Heath notes in a November 2025 article for The War Zone (TWZ) that China’s growing inventory of advanced, hard-to-track systems such as stealth aircraft, hypersonic missiles and directed energy weapons (DEWs) may outpace US counters.
Also, Robert Peters stresses in the article that China’s mass production of fighters, ships and missiles, which—despite uncertain quality—creates a concentrated regional advantage against globally dispersed US forces.
But in the same report, Brad Bowman mentions that China may be trying to inundate US intelligence with reveal after reveal to confuse hype with real capability, while sprinting towards capabilities necessary to take Taiwan.
In addition, Zack Cooper states in the report that while only a few of China’s reveals are actually completely new systems, analyzing each reveal still requires time and resources, thus becoming a significant strain on intelligence capabilities.
If China eventually closes the technological and defense-industrial gap with the US, that situation could lead to the US equivalent of the “Suez Crisis,” according to Bence Nemeth in a 2025 article for the Texas National Security Review (TNSR) journal.
Nemeth argues that such an event—whether a disastrous defeat, refusal to intervene in a Taiwan conflict or a limited skirmish in the South China Sea—exposing US weakness would make the US’s decline obvious to the world. He emphasizes that the resulting psychological rupture could shatter the credibility of US security guarantees across its alliance system in the Pacific.
He also argues that such a shock would not collapse US alliances outright but would push them toward either hollowing out – reduced to mere symbolism without substance or adaptation – US dominance giving way to a more distributed and negotiated security order.
In a hollowing-out scenario, South Korea may face intensified pressure to pursue nuclear weapons if confidence in US extended deterrence collapses. Japan, while unlikely to move immediately toward nuclearization, possesses significant nuclear latency, and a similar credibility shock could bring long-suppressed arguments for an independent nuclear deterrent back into serious strategic debate.
Some Philippine nationalists and politicians, banking on historical colonial grievances and sovereignty concerns regarding the US military presence in the country, would gain wider support.
A US debacle in the Taiwan Strait or in the South China Sea may raise questions about the US military presence in the country, which could then prompt Philippine leaders to scale down combined exercises or even revoke US access to Philippine military facilities.
Similarly, such a blow to US credibility could push Australia and New Zealand toward rapprochement with China, given their heavy trade reliance on China as their primary export market.
A less bleak outcome is adaptation, where the US loses its primacy but keeps core alliance elements like political alignment, cooperation and niche capabilities, acting more as an enabler than a leader in a distributed security architecture.
In this connection, Japan has signed Reciprocal Access Agreements (RAAs) with Australia and the Philippines. Similarly, the Philippines has expanded its defense partnerships beyond the US to include Japan, Australia, Canada and New Zealand.
While these defense partnerships do not replace the bilateral US alliance system, they build on the latter – filling in capability gaps while avoiding the onerous obligations of treaty alliances.
Viewing US capabilities as enablers, US space-based intelligence, surveillance and reconnaissance (ISR) may be essential in helping Japan execute its counterstrike options against China and North Korea—addressing a critical capability gap until Japan can develop its own.
South Korea might choose to sustain its strong military ties with the US while continuing to build its independent conventional forces and working toward the eventual transfer of wartime operational command (OPCON) from the US.
US space-based ISR and command and control (C2) could enhance the Philippines’ maritime domain awareness (MDA), allowing the country to conduct resupply missions to its South China Sea outposts and respond effectively to China’s gray zone provocations, enabling Manila to take the lead in asserting its territorial claims.
While Australia remains a hub for sensitive US military technology, such as nuclear propulsion for the planned AUKUS nuclear attack submarines (SSN-AUKUS), it may decide that US security guarantees alone are not enough for its security. Australia could thus revitalize its longstanding Five Power Defense Arrangement (FPDA) with the UK, Singapore, Malaysia and New Zealand.
Taken together, the Overmatch brief may matter less as a warning than as an acknowledgment that the Indo-Pacific is already adapting to a strategic landscape in which US military primacy can no longer be assumed.
The more immediate question, then, is not how the US restores unquestioned military-industrial dominance but how effectively it adjusts to a region learning to operate without it.
