Over the past twenty years, a revolution has occurred in relations between the American executive and legislative branches. Once a passive observer of the President''s decisions on defense policy, the Congress has assumed a more aggressive role in decisions on the defense budget, arms control, war powers, sales of weapons abroad, and covert operations. Based on interviews with members of Congress and their staffs, The Politics of National Security describes and analyzes this fundamental change in the United States political system, concentrating on the political factors behind the Congress'' greater assertiveness.