In their initial effort to end the Vietnam War, Richard Nixon and Henry Kissinger attempted to lever concessions from Hanoi at the negotiating table with military force and coercive diplomacy. They were not seeking military victory, which they did not believe was feasible. Instead, they backed up their diplomacy toward North Vietnam and the Soviet Union with the Madman Theory of threatening excessive force, which included the specter of nuclear force. They began with verbal threats then bombed North Vietnamese and Viet Cong base areas in Cambodia, signaling that there was more to come. As the...