Book excerpt: In numerous crises after World War II--Berlin, Korea, the Taiwan Straits, and the Middle East--the United States resorted to vague threats to use nuclear weapons in order to deter Soviet or Chinese military action. On a few occasions the Soviet Union also engaged in nuclear saber-ratling. Using declassified documents and other sources, this volume examines those crises and compares the decisionmaking processes of leaders who considered nuclear threats with the commonly accepted logic of nuclear deterrence and coercion. Rejecting standard explanations of our leader's logic in these cases, Betts suggests that U.S. presidents were neither consciously blufffing when they made nuclear threats, nor prepared to face the consequences if their threats failed. The author also challenges the myth that the 1950s was a golden age of low vulberability for the nted Stateas and details how nuclear parity has, and has not, altered conditions that gave rise to nuclear blackmail in the past.