If China Invaded Taiwan: Who Would Enter the War?

An outright Chinese invasion of Taiwan would be one of the most destabilizing events imaginable for Asia and the entire global order. This scenario raises urgent questions about which countries, if any, would intervene militarily to defend Taiwan. Analysts stress that much would depend on the circumstances – above all, the role of the United States. It is widely assessed that without a U.S. military intervention, Taiwan would likely stand alone, as no other nation is expected to commit forces unilaterally against China. However, if the United States were to intervene, it could trigger a broader coalition response, drawing in regional allies and partners – albeit with varying degrees of reluctance, capability, and risk. In essence, who enters the war (and to what extent) hinges on strategic calculations of deterrence and alliance commitments under fire. This report provides a comprehensive analysis, akin to a think-tank assessment, of the potential military responses by key countries and groups of countries in the event of a Chinese invasion of Taiwan. It evaluates all major hypotheses, from U.S. neutrality to full U.S.-led coalition defense, and considers how each actor’s response might shape the conflict’s course. Throughout, the focus remains on military responses and deterrence scenarios, drawing only on authoritative sources and avoiding speculative or purely journalistic accounts.