In October 1981, the Administration announced its plan to modernize all parts of the U.S. strategic deterrent. Representing the most comprehensive and far-reaching such effort in the past 20 years, the plan would expand and upgrade the triad of strategic "offensive" forces: land-based and sea-based intercontinental ballistic missiles plus long-range bombers. It would also improve the triad's communications and control systems, and strengthen U.S. defenses against attack by Soviet bombers. U.S. strategic forces are primarily intended to deter the Soviet Union from initiating a nuclear war. To do so, they must be able to survive a Soviet nuclear strike and retaliate in an appropriate and timely manner. In recent years, the Soviets have expanded and improved their strategic forces. The Administration apparently believes that in response the United States must increase not only the numbers of its forces and their chance of surviving a Soviet strike, but also their destructive capability, endurance, and responsiveness. The broad scope of the buildup and the relative share of the nation's resources to be devoted to defense in general has sparked debate, as has the high cost of individual weapons systems. Most recently, debate has centered on the Administration's proposal to deploy the MX missile. This study assesses the scope and costs of the Administration's planned modernization, taking into consideration the effects that arms control agreements could have on it. The study also considers proposals to modify the Administration's program by (1) dropping the MX missile, (2) focusing modernization efforts on submarine-based missiles rather than land-based missiles, or (3) terminating the B-1B bomber program in favor of improving existing bomber capability.