The evolution of U.S. policy and the antiterrorism bureaucracy and command structure are traced from President Nixon's creation of the cabinet committee to combat terrorism to President Reagan's signing of National Security Decision Directive 138, sanctioning the use of more aggressive counterterrorist actions, such as the U.S. raid on Libya. In addition to defining terrorism and outlining the U.S. and international responses to it, this study presents the strengths and weaknesses of U.S. antiterrorism tactics. Among the recommendations for enhancing U.S. antiterrorism efforts is the establishment of the Office of Low-Intensity Conflicts within the National Security Council, with the purposes of facilitating policy formulation and implementation and improving the handling of crises. Appended list of the heads of the State Department's Antiterrorist Office from 1972 to 1987, subject index, and 91-item bibliography. (Publisher summary modified)