Defense planners appear to believe that they can win a short conflict in the Taiwan Strait merely by blunting a Chinese invasion. Chinese leaders, for their part, seem to envision rapid, paralyzing strikes that break Taiwanese resistance and present the United States with a fait accompli. Both sides would prefer a splendid little war in the western Pacific, but that is not the sort of war they would get.

A war over Taiwan is likely to be long rather than short, regional rather than local, and much easier to start than to end. It would expand and escalate, as both countries look for paths to victory in a conflict neither side can afford to lose. It would also present severe dilemmas for peacemaking and high risks of going nuclear. If Washington doesn’t start preparing to wage, and then end, a protracted conflict now, it could face catastrophe once the shooting starts.