How likely is China to start a war? This may be the single-most important question in international affairs today. If China uses military force against Taiwan or another target in the Western Pacific, the result could be war with the United States—a fight between two nuclear-armed giants brawling for hegemony in that region and the wider world. If China attacked amid ongoing wars in Ukraine and the Middle East, the world would be consumed by interlocking conflicts across Eurasia’s key regions, a global conflagration unlike anything since World War II.