Efforts of the United States since the end of World War II to advance the arms control process are discussed. There are five major sections. The first section recounts past arms control efforts--those that have worked and those that have not--and discusses the principles underlying U.S. arms control initiatives. The second section describes the factors that have shaped U.S. security policy, examining security in Asia, the Near East and Southwest Asia, the Western Hemisphere, Africa, and Europe. The North Atlantic Treaty Organization (NATO) and the strategic defense initiative are also examined. The role of arms control in U.S. security and the Soviet approach to arms control are examined in the third section. The fourth section reports on eight critical arms control challenges and how the United States and its allies are addressing them. The challenges are: strategic arms reduction talks, intermediate-range nuclear forces, mutual and balanced force reductions, confidence-building measures, chemical weapons, space arms control, nuclear testing, and nuclear nonproliferation. The publication concludes by summarizing the prospects for arms control. An arms control glossary is provided. (RM)