In the wake of agreeing to a two-week cease-fire on April 7, both the United States and Iran are claiming victory in their war. Each says the same thing: We held out and the other guy blinked first. In fact, both decided to call it a draw. And some sort of outcome like this was always likely, because the structure of the game constrained the decision-making of the players—even players as idiosyncratic as U.S. President Donald Trump and the leaders of the Islamic Republic. Wars have three phases: