The interagency: NSC, State, DoD & intelligence
How the NSC, State, DoD, and the intelligence community share, contest, and coordinate US foreign policy—the legal architecture and practice the FSOT tests.
The National Security Act of 1947
The modern US national-security apparatus is the creation of a single statute: the National Security Act of 1947 (Pub. L. 80-253), signed by President Truman on July 26, 1947. It did four structural things. First, it created the National Security Council (NSC) to advise the President on the integration of domestic, foreign, and military policy. Second, it established the Central Intelligence Agency (CIA) under a Director of Central Intelligence. Third, it created an independent Department of the Air Force. Fourth, it laid the groundwork for unifying the armed services under what the 1949 amendments renamed the Department of Defense (DoD), headed by a civilian Secretary.
The NSC's statutory members are fixed by law: the President, Vice President, Secretary of State, and Secretary of Defense, with the Chairman of the Joint Chiefs of Staff as statutory military adviser and the Director of National Intelligence (DNI) as statutory intelligence adviser. The National Security Advisor (Assistant to the President for National Security Affairs) runs the NSC staff but—critically—is not Senate-confirmed and does not appear in the statute as a principal. Every president since Truman has reshaped the NSC by executive directive: Eisenhower built a formal planning-board structure; Kennedy dismantled it after the Bay of Pigs (April 1961); Nixon and Kissinger centralized policy in the West Wing; and each administration issues its own series of directives (PDDs, NSDDs, PPDs, NSPMs).
State, Defense, and the Intelligence Community
The Department of State, created in 1789 as the first executive department, is the lead foreign-affairs agency; the Secretary of State is fourth in the presidential line of succession and the highest-ranking Cabinet officer. Under the Foreign Service Act of 1980, the career Foreign Service staffs roughly 270 diplomatic posts. At each post the chief of mission (ambassador) holds authority over all US executive-branch personnel under the doctrine codified in 22 U.S.C. § 3927 and reinforced by the President's standing 'Letter of Instruction'—except those under a geographic combatant commander.
The Department of Defense projects force through the unified combatant commands (e.g., CENTCOM, INDOPACOM) established under the chain of command running from the President to the Secretary of Defense to the combatant commanders—a structure cemented by the Goldwater-Nichols Act of 1986, which stripped the service chiefs of operational command and made the CJCS the principal military adviser. The Intelligence Community, comprising 18 elements coordinated by the DNI under the Intelligence Reform and Terrorism Prevention Act of 2004 (IRTPA), feeds the National Intelligence Estimates and the President's Daily Brief. These four poles—NSC convener, State diplomat, DoD warfighter, IC analyst—form the interagency that the FSOT expects you to navigate.