First-Strike Stability

This report presents a logical and transparent methodology for evaluating strategic offensive forces on the basis of first-strike stability, which the authors define as a condition that exists when neither superpower perceives the other as motivated by the strategic force posture to launch the first nuclear strike in a crisis. The methodology underlines that (1) first-strike stability under current conditions is relatively robust, (2) postures of U.S. and Soviet strategic nuclear forces become increasingly important under an arms reduction regime if the current level of first-strike stability is desired, (3) enlarging U.S. and Soviet strategic nuclear weapons inventories does not necessarily erode first-strike stability, (4) the superpowers should realize the importance of both sides generating forces early in a crisis to render these forces nontargetable, and (5) whatever the index of first-strike stability, the index applies equally to both the United States and the Soviet Union, and thus suggests a dimension of U.S.-Soviet cooperation.