This study of Soviet and US strategies for air and ballistic missile defense addresses two broad subjects: (1) How did each country approach the problem of defense against the threat from the air? (2) Why did each country accent particular elements of an air defense strategy at various periods between 1945 and 1972? The scope and pace of technological innovations introduced a measure of uncertainty, placed considerable strain on the stability of the U.S.-Soviet relationship, and raised fundamental challenges to previous concepts of how best to defend. U.S. strategy was built on the variety of new weapon system developments; while Soviet defense trends demonstrated Soviet awareness and responded to developments in U.S. strategic offensive forces. The basic patterns of action were set by initial, and early, strategic choices. (Originally published by the Army Center for Military History)