Established during World War II to advise the President regarding the strategic direction of the armed forces of the United States, the Joint Chiefs of Staff (JCS) continued in existence after the war and, as military advisers and planners, have played a significant role in the development of national policy. Knowledge of JCS relations with the President, the National Security Council, and the Secretary of Defense in the years since World War II is essential to an understanding of their current work. An account of their activity in peacetime and during times of crisis provides, moreover, an important series of chapters in the military history of the United States. For these reasons, the Joint Chiefs of Staff directed that an official history be written for the record. Its value for instructional purposes, for the orientation of officers newly assigned to the JCS organization, and as a source of information for staff studies will be readily recognized. The series, The Joint Chiefs of Staffand National Policy, treats the activities of the Joint Chiefs of Staff since the close of World War II. Because of the nature of the activities of the Joint Chiefs of Staff as well as the sensitivity of the sources, the volumes of the series were originally prepared in classified form. Classification designations, in text and footnotes, are those that appeared in the original classified volume. Following review and declassification, the initial four volumes, covering the years 1945 to 1952 and the Korean War, were distributed in unclassified form within the Department of Defense and copies were deposited with the National Archives and Records Administration. These volumes are now being made available as official publications. Volume III describes the participation of the Joint Chiefs of Staff in the Korean War; their other activities during the period are covered in Volume IV, except for activities related to Indochina which are covered in a separate series. This volume was originally planned by Mr. Wilber W Hoare, who developed an outline and drafted six of the first seven chapters. Following a lapse of some years, these drafts were revised and expanded by Dr. Walter S. Poole, under the direction of Mr. KennethW Condit. Meanwhile, other chapters, or portions thereof, had been prepared by Miss Martha Derthick, Mr. Morris MacGregor, and Miss Barbara Sorrill. In 1968, Dr. Robert J. Watson was assigned as the responsible author. He reviewed existing drafts, carried out additional research, and wrote Chapters 1 through 9 in essentially their present form. When he was transferred to other duties, Mr. James F. Schnabel assumed responsibility for the volume and planned, researched, and wrote the remaining eight chapters. Subsequently, all of the chapters were reviewed and revised by both Mr. Schnabel and Dr. Watson. Final revision and historical editing proceeded under the supervision of Dr. Watson in his capacity as Chief, Histories Branch, and of his successor in that position, Mr. Kenneth W. Condit.