Although today’s world is fraught and fragile, the rules-based order is in many ways in good shape. The broad coalition of Western democracies, undergirded militarily by American armed forces and nuclear deterrence, collectively accounts for at least two-thirds of world GDP and defense spending.

Alliances like that between Japan and the United States are further buttressed by the forward deployment of U.S. combat units and realistic exercises. Deterrence seems to be working. The absence of a war between great powers since 1953 is testament to how much we have collectively gotten right in strategic terms — even as new threats such as COVID-19 test our every capacity and demand cooperation with countries like China to the extent possible.

Yet as noted, the world is fragile, and thus none of this is guaranteed to last. Perhaps the most likely path to a great-power war in today’s world would be a crisis over Taiwan that spins out of control.