Why Disarmament? Why Now? Multipolarity 15 Deterrence diluted 17 Nuclear realism 19 Defining disarmament 22 The new nuclear moment 26

Calls for nuclear disarmament are as old as the nuclear age. The awesome, destructive power unleashed on the cities of Hiroshima and Nagasaki in 1945 prompted immediate political plans to put the weapon under international control and prevent its use again, with atomic energy confined solely to

peaceful purposes. The United States and the Soviet Union were unable to agree, however, as the competition for power in the post-war world and a lack of mutual trust stood in the way of disarmament.