US vs China: Who would win if war went nuclear?

In a tabletop exercise conducted by the Centre for a New American Security (CNAS), a think-tank in Washington, experts explored the chilling scenario of a Sino-American nuclear war breaking out in the year 2032. The results of the wargame were sobering, highlighting the potential for a nuclear conflict to emerge from a conventional war over Taiwan, with devastating consequences.
The scenario posited that after 45 days of intense warfare over Taiwan, China might resort to using “theatre” nuclear weapons—shorter-range and lower-yield compared to the strategic nuclear missiles designed to target cities.These weapons could be used in an attempt to coerce the United States into submission by targeting key military assets such as Guam, Kwajalein Atoll, and an American aircraft carrier strike group.
The authors - Andrew Metrick, Philip Sheers and Stacie Pettyjohn - employed two TTXs to explore the dynamics of nuclear coercion in a hypothetical 2032 conflict over Taiwan. The exercises, named "Spike the Ball" and "Cold Stop," tested different scenarios where China might use nuclear weapons to either consolidate a marginal advantage or compensate for a disadvantage. The results highlighted the complexity of managing nuclear escalation in such a conflict and the challenges facing US decision-makers.
US and Chinese nuclear capabilities
From a capabilities standpoint, the United States maintains a more extensive and advanced nuclear arsenal compared to China. The US possesses a diversified triad of nuclear forces, comprising land-based intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and strategic bombers. This triad provides the US with significant second-strike capabilities, ensuring that it can retaliate effectively even after a nuclear attack.
China, on the other hand, has traditionally maintained a smaller and more conservative nuclear force. However, recent years have seen a significant expansion and modernization of China's nuclear arsenal. China's development includes new mobile missile systems, enhancements to submarine-launched ballistic missiles, and the construction of numerous hardened ICBM silos. By 2030, China is expected to have around 1,000 operational nuclear warheads.
"China is expanding its nuclear arsenal faster than any other country. But in nearly all of the nuclear-armed states there are either plans or a significant push to increase nuclear forces," said Hans M Kristensen, an associate senior fellow with SIPRI.

Despite this growth, China’s nuclear doctrine historically emphasized a no-first-use policy and maintained a strategy focused on assured deterrence rather than nuclear warfighting. However, the expansion and modernization efforts suggest that China may be moving towards a more flexible and potentially more aggressive nuclear posture. This shift could involve adopting a launch-on-warning posture and integrating nonstrategic nuclear weapons into its conventional warfighting strategies .
Escalation pathways and potential outcomes
The potential pathways to nuclear escalation between the US and China are complex and fraught with risks. A key finding of the study is that a protracted conflict, particularly one involving a crisis over Taiwan, creates conditions where nonstrategic nuclear weapons use becomes increasingly appealing for China.
As conventional capabilities become strained, China might consider limited nuclear strikes, despite its formal “No First Use” policy, to achieve favorable terms or to coerce the US into de-escalating the conflict.

If China were to initiate limited nuclear strikes, especially against US military targets or allied territories in the Indo-Pacific, the US would face a critical decision point. The study’s tabletop exercises (TTXs) indicate that US decision-makers might struggle to respond uniformly to such provocations. Some might advocate for a proportional nuclear response, while others could argue that US interests in Taiwan do not justify the risks of further nuclear escalation .
The role of allies and global impact
Another critical factor in a US-China nuclear conflict is the role of US allies in the region. The study notes that China could use nuclear coercion against US allies, such as Japan or Australia, to weaken the US alliance network and strain its extended deterrence commitments. Such actions would not only challenge US resolve but also potentially fragment the alliance, making it more difficult for the US to maintain a unified front against Chinese aggression .
The global impact of a nuclear war between the US and China would be catastrophic, with consequences far beyond the immediate destruction caused by nuclear weapons. Economically, politically, and environmentally, the effects would be felt worldwide, making the very concept of "winning" in such a conflict meaningless.
"The political ramifications of nonstrategic nuclear use are highly variable and unpredictable. While there is a clear operational utility to nuclear arms, their political impacts are far less certain, resulting in a wide range of different beliefs within the expert community," the report notes.
Key findings and recommendations
The report concludes with several key findings and recommendations for US policymakers: