Consider a game that theorist Thomas Schelling described to his students at Harvard in the '60s: You're standing at the edge of a cliff, chained by the ankle to another person. As soon as one of you cries uncle, you'll both be released, and whoever remained silent will get a large prize. What do you do? You can't push the other person off the cliff, because then you'll die, too. But you can dance and walk closer and closer to the edge. If you're willing to show that you'll brave a certain amount of risk, your partner may concede — and you might win the prize. But if you convince your adversary that you're crazy and liable to hop off in any direction at any moment, he'll probably cry uncle immediately. If the US appeared reckless, impatient, even insane, rivals might accept bargains they would have rejected under normal conditions. In terms of game theory, a new equilibrium would emerge as leaders in Moscow, Hanoi, and Havana contemplated how terrible things could become if they provoked an out-of-control president to experiment with the awful weapons at his disposal.