The National Security Act of 1947 created the Central Intelligence Agency (CIA), America's first peacetime, civilian intelligence organization. The director of central intelligence (DCI) heads the CIA, is the president's chief intelligence advisor, and coordinates U.S. intelligence activities.

Before establishing the CIA, President Truman questioned the need for a centralized intelligence structure. The legacy of Pearl Harbor and concerns about expansion by the Soviet Union into Western Europe overcame Truman's antipathy toward a secret intelligence organization. However, decisions made then involved compromises, and later bureaucratic and political compromises have created a diverse intelligence community of which the CIA is only one part. The CIA's mandate made it the leading governmental entity for gathering, processing, and disseminating foreign intelligence for national policymakers. Growing tensions early in the Cold War led to an expansion of that role to include responsibility for political and paramilitary covert activities...