Defense, United States Department of definition of Defense, United States Department of in the Free Online Encyclopedia.

Defense, United States Department of, executive department of the federal government charged with coordinating and supervising all agencies and functions of the government relating directly to national security and military affairs. Based in the Pentagon Pentagon, the, building accommodating the U.S. Dept. of Defense. Located in Arlington, Va., across the Potomac River from Washington, D.C., the Pentagon is a five-sided building consisting of five concentric pentagons connected to each other by corridors and covering
..... Click the link for more information. , it is divided into three major subsections—the U.S. Army, the U.S. Navy, and the U.S. Air Force. Among the many Defense Dept. agencies are the Missile Defense Agency (see Strategic Defense Initiative Strategic Defense Initiative (SDI), U.S. government program responsible for research and development of a space-based system to defend the nation from attack by strategic ballistic missiles (see guided missile ).
..... Click the link for more information. ), the Defense Advanced Research Projects Agency, the Defense Intelligence Agency, the National Geospatial-Intelligence Agency, and the National Security Agency National Security Agency (NSA), an independent agency within the U.S. Dept. of Defense. Founded by presidential order in 1952, its primary function is to encode and decode communications intelligence and to protect U.S. signals and information systems.
..... Click the link for more information. . The department also operates several joint service schools, including the National War College.

Creation

The Dept. of Defense was created by the National Security Act of 1947 by combining the Depts. of War War Department, United States, federal executive department organized (1789) to administer the military establishment. It was reconstituted (1947) as the Dept. of the Army when the military administration was reorganized (see Defense, United States Department of ).
..... Click the link for more information. and Navy and was called the National Military Establishment; it became the Dept. of Defense when the act was amended (1949). James V. Forrestal Forrestal, James Vincent (fôr`ĭstôl', fŏr`–), 1892–1949, U.S.
..... Click the link for more information. pioneered in this reorganization. Under the act, the Secretary of Defense—appointed by the President with the consent of the Senate—supervises the entire military. Under the Secretary of Defense is the Joint Chiefs of Staff Joint Chiefs of Staff, U.S. statutory agency, created in 1949 within the Dept. of Defense. The chairman is the principal military adviser to the President, the National Security Council, and the Secretary of Defense.
..... Click the link for more information. made up of its chairperson, a senior military officer, the heads of the three main services, and the Commandant of the Marine Corps Marine Corps, United States, military corps that forms a separate service within the U.S. Dept. of the Navy. The commandant of the Marine Corps is a member of the Joint Chiefs of Staff .
..... Click the link for more information. . The Secretary of the Army, the Secretary of the Navy, and the Secretary of the Air Force—made cabinet members by the act of 1947—were subordinated (1949) to give the Secretary of Defense full cabinet authority over the department.

History

The new defense establishment received its first test in the Korean War Korean War, conflict between Communist and non-Communist forces in Korea from June 25, 1950, to July 27, 1953. At the end of World War II, Korea was divided at the 38th parallel into Soviet (North Korean) and U.S. (South Korean) zones of occupation.
..... Click the link for more information. . It was generally agreed that the department revealed a capability to react quickly to crisis, but there was criticism that too much reliance had been placed on strategic air forces air forces, those portions of a nation's military organization employing heavier-than-air aircraft for reconnaissance, support of ground troops, aerial combat, and bombing of enemy lines of communication and targets of industrial and military importance.
..... Click the link for more information. and nuclear weapons nuclear weapons, weapons of mass destruction powered by atomic, rather than chemical, processes. Nuclear weapons produce large explosions and hazardous radioactive byproducts by means of either nuclear fission or nuclear fusion.
..... Click the link for more information. to the neglect of conventional military forces. The Eisenhower administration, concerned about controlling military expenditures, emphasized deterring a nuclear attack with massive retaliation (see nuclear strategy nuclear strategy, a policy for the use of nuclear weapons . The first atomic bombs were used in the context of the Allies' World War II policy of strategic bombing. Early in the cold war , U.S.
..... Click the link for more information. ), despite critics who advocated additional expenditures on conventional forces.

Under Secretary of Defense Robert S. McNamara McNamara, Robert Strange (măk`nəmâr'ə), 1916–, U.S. Secretary of Defense (1961–68), b. San Francisco.
..... Click the link for more information. (1961–68), the department aimed for a more balanced military program and established a new layer of civilian officials who imported civilian management techniques. In general, the administrations of Presidents John F. Kennedy Kennedy, John Fitzgerald, 1917–63, 35th President of the United States (1961–63), b. Brookline, Mass.; son of Joseph P. Kennedy .

Early Life

..... Click the link for more information. and Lyndon Johnson Johnson, Lyndon Baines, 1908–73, 36th President of the United States (1963–69), b. near Stonewall, Tex.

Early Life

Born into a farm family, he graduated (1930) from Southwest Texas State Teachers College (now Southwest Texas State Univ.
..... Click the link for more information. aimed for a stronger conventional capability but still failed with their counterinsurgency strategy in the Vietnam War Vietnam War, conflict in Southeast Asia, primarily fought in South Vietnam between government forces aided by the United States and guerrilla forces aided by North Vietnam.
..... Click the link for more information. .

During the cold war cold war, term used to describe the shifting struggle for power and prestige between the Western powers and the Communist bloc from the end of World War II until 1989.
..... Click the link for more information. , the Dept. of Defense became a major economic force, mostly through its massive purchases and research investments (see Defense Advanced Research Projects Agency Defense Advanced Research Projects Agency (DARPA), U.S. government agency administered by the Department of Defense (see Defense, United States Department of ).
..... Click the link for more information. ). However, the breakup of the USSR and the resultant reductions in defense spending have negatively affected civilian industries that supplied the Dept. of Defense. By 1997 the department had begun a "defense reform initiative," intended to streamline and modernize what had become one of the world's largest organizations.

Bibliography

See W. Millis, Arms and Men: A Study of American Military History (New York: Mentor Books),1956; C. W. Borklund, The Department of Defense (1968) and with G. Foster, Paradoxes of Power (1983).