National Security Act

The National Security Act created the modern governmental bureaucratic structure responsible for the defense of the United States. It created the Department of Defense and the cabinet-level post of secretary of defense, as well as the National Security Council, the Central Intelligence Agency, and the Joint Chiefs of Staff.

Summary of Event

As steps were taken to strengthen the U.S. commitment to European security by means of the Truman Doctrine and the Marshall Plan, it became increasingly clear that measures were needed at home to increase the efficiency of the United States’ military establishment. A major impetus to the reorganization of the U.S. defense system had come from the obvious weaknesses revealed during World War II. One prime example of such weaknesses was the military disaster at Pearl Harbor. The war also had revealed numerous cases of duplication of effort among the various services. Another new factor that needed to be considered was that Cold War diplomacy required close collaboration between military and diplomatic elements, a condition that had hardly existed during the war. Therefore, many officials, including President Harry S. Truman, thought that the need for a more efficient system of defense was obvious. National Security Act (1947)
Department of Defense, U.S.
Central Intelligence Agency;establishment
National Security Council
Joint Chiefs of Staff, U.S.
Armed forces, U.S.
Cabinet, U.S., reorganization of
[kw]National Security Act (July 26, 1947)
[kw]Security Act, National (July 26, 1947)
[kw]Act, National Security (July 26, 1947)
National Security Act (1947)
Department of Defense, U.S.
Central Intelligence Agency;establishment
National Security Council
Joint Chiefs of Staff, U.S.
Armed forces, U.S.
Cabinet, U.S., reorganization of
[g]North America;July 26, 1947: National Security Act[02100]
[g]United States;July 26, 1947: National Security Act[02100]
[c]Laws, acts, and legal history;July 26, 1947: National Security Act[02100]
[c]Government and politics;July 26, 1947: National Security Act[02100]
Truman, Harry S.
[p]Truman, Harry S.;national security agencies
Forrestal, James Vincent
Patterson, Robert Porter
Johnson, Louis A.
Bradley, Omar N.
Marshall, George C.
[p]Marshall, George C.;as secretary of defense[secretary of defense]
Nixon, Richard M.
[p]Nixon, Richard M.;and Henry Kissinger[Kissinger]

From left: Chairman of the Joint Chiefs of Staff General Omar N. Bradley, Secretary of Defense Louis A. Johnson, President Harry S. Truman, and an unidentified official watch an Army Day parade in 1949.

(National Archives)

On July 26, 1947, Truman signed the National Security Act, responding to this need, but reaching an agreement on the exact details of the reorganization and centralization of the military establishment had not been an easy task. As early as 1945, President Truman had submitted a plan for reorganization to Congress, but it took two years to settle the differences of opinion among the three branches of the armed forces. The Navy was especially reluctant to sacrifice its independence to what it feared would be a defense establishment dominated by the Army. In particular, the Navy feared that the new system might mean the abolishment of the Marines, or at least their transferral to the Army.

Another sensitive area of dispute centered on the Navy’s newly acquired air capability. Having become firmly convinced of the value of aircraft carriers during World War II, the Navy wanted to expand its air arm, which would include the construction of super-carriers able to accommodate the newly designed jet planes. Many admirals feared that an Army-dominated defense system might mean an emphasis on land-based, long-distance bombers. During 1946 and 1947, President Truman worked to bring together the Army, represented by Secretary of War Robert Porter Patterson, and the Navy, represented by Secretary of the Navy James Vincent Forrestal. In this campaign, Truman was assisted especially by Forrestal, who, although entirely sympathetic to the Navy’s point of view, did work for a reasonable compromise.

As a result of these meetings, agreements were reached that culminated in the National Security Act of 1947. The act created the Department of Defense (called the National Military Establishment until 1949) with a secretary holding cabinet rank. The Department of the Army, the Department of the Navy, and a new Department of the Air Force were made into separate subcabinet agencies within the Department of Defense. The act also gave legal recognition to the Joint Chiefs of Staff, with a rotating chairman. Each of the three services would be represented on this committee, which was to be responsible for providing close military coordination, preparing defense plans, and making strategy recommendations to another new agency, the National Security Council, which was to be chaired by the president of the United States.

The other members of the National Security Council were to include the vice president, the secretary of state, the secretary of defense, the secretaries of the three services, and the chairman of another new agency, the National Security Resources Board. The president could designate additional persons to serve on the council; under Truman, the council had twenty members. Critics labeled the council “Mr. Truman’s Politburo,” because it attempted to blend diplomatic and military considerations at the highest level of national interest. Finally, the act created the Central Intelligence Agency as an independent source of security information.

This impressive reorganization plan had barely gotten under way when serious problems arose. In some instances, these problems were merely continuations of the traditional competition between the Army and the Navy; the new system did little to eliminate interservice rivalry, despite the outstanding work of Forrestal as the first secretary of defense. Some opponents asserted that the new system merely created one more contending party, the Air Force. The three services soon were engaged in conducting separate, elaborate publicity and congressional lobbying campaigns to gain increased shares of the defense budget. The Navy championed the merits of its super-carrier program, while the Air Force pointed to the new B-36 bomber as the best defense investment. Secretary Forrestal tried to mediate this struggle, but the issues seemed to be beyond the capacity of any one person to control. In failing health, the secretary resigned on March 3, 1949. Although interservice rivalry still existed, Forrestal had reported prior to his resignation that the new defense system had already saved U.S. taxpayers more than $56 million.

The new secretary of defense appointed by President Truman was Louis A. Johnson of West Virginia, who approached his job with a pugnacious attitude that may have been a result of his lack of administrative experience at a comparably high level of government employment. He soon plunged into the interservice rivalry by favoring the Air Force. The building of new naval aircraft carriers was suspended, and considerable amounts of money went into expanding the strength of the Air Force. Although this executive policy saved money, some critics claimed that it weakened national defense. The State Department joined in the growing criticism of Johnson, because it resented the new secretary’s unilateral approach to national security. Apparently, it was not long before Truman had reason to regret his appointment of Johnson, as in September, 1950, he turned to General George C. Marshall, former secretary of state, to take over the Department of Defense. The simultaneous appointment of Marshall’s service colleague, General Omar N. Bradley, as chairman of the Joint Chiefs of Staff helped make operations smoother within the Defense Department.


The full implications of the new diplomatic and military structures created by the National Security Act did not become evident until the administration of President Richard M. Nixon. Nixon’s national security adviser and secretary of state, Henry Kissinger Kissinger, Henry , established the supremacy of those two positions over the rest of the foreign policy apparatus. Although efforts were made to decentralize that apparatus after Kissinger’s departure, his legacy continued into subsequent administrations.

The overall result of the National Security Act was to create a U.S. foreign policy system that fit the country’s new and unprecedented role as a global superpower. The law also created a system in which the national security adviser became a major player in foreign policy decisions, enjoying daily direct access to the president as an integral member of the executive branch of the government. More than one secretary of state would complain about having to do battle with influential national security advisers who had the president’s ear. Finally, the legal requirement that the secretary of defense not be an active member of the military cemented the tradition of the U.S. military being commanded at its highest levels by civilians, a policy that would have far-reaching effects throughout the twentieth and early twenty-first centuries. National Security Act (1947)
Department of Defense, U.S.
Central Intelligence Agency;establishment
National Security Council
Joint Chiefs of Staff, U.S.
Armed forces, U.S.
Cabinet, U.S., reorganization of

Further Reading

  • Destler, I. M. “National Security Advice to U.S. Presidents: Some Lessons from Thirty Years.” World Politics 29, no. 2 (January, 1977): 143-176. An analysis and critique of the foreign policy advisory system created by the National Security Act. Although thorough and based on three decades of experience, the analysis is now somewhat dated.
  • Hoxie, R. Gordon. “James V. Forrestal and the National Security Act of 1947.” In Command Decision and the Presidency: A Study in National Security Policy and Organization. New York: Readers Digest Press, 1977. Discusses the origins and provisions of the National Security Act; provides particular detail on the 1949 amendment to the act. Written in a narrative style. Notes and bibliography.
  • Leffler, Melvyn P. A Preponderance of Power: National Security, the Truman Administration, and the Cold War. Stanford, Calif.: Stanford University Press, 1992. Places the National Security Act within the larger context of the Cold War. See especially chapter 4, “From the Truman Doctrine to the National Security Act, November 1946-July 1947.” Notes and bibliography.
  • Rosati, Jerel A. “Presidential Management and the NSC Process.” In Politics of United States Foreign Policy. Fort Worth, Tex.: Harcourt Brace Jovanovich, 1993. Discusses the foreign-policy-making system created by the National Security Act. Clear and well organized. Tables, charts, and bibliographic essay.
  • Stuart, Douglas T. “Present at the Legislation: The 1947 National Security Act.” In Organizing for National Security, edited by Douglas T. Stuart. Carlisle Barracks, Pa.: Strategic Studies Institute, U.S. Army War College, 2000. Essay detailing the 1947 act and its importance to U.S. national security structures. The rest of the volume examines changes in that structure throughout the rest of the twentieth century. Bibliographic references.
  • Theoharis, Athan G., ed. The Truman Presidency: The Origins of the Imperial Presidency and the National Security State. Stanfordville, N.Y.: Earl M. Coleman Enterprises, 1979. A compilation of extracts from declassified memos, addresses, letters, and analyses, with commentary by the editor. The chapter on the political and legislative history of the National Security Act and the 1949 amendments is especially useful. Notes and bibliography.

Truman Doctrine

Marshall Plan Provides Aid to Europe

Truman-MacArthur Confrontation

Eisenhower Warns of the Military-Industrial Complex

Freedom of Information Act Goes into Effect

Nixon Is Elected President