National Security Act of 1947 in the context of "Military intelligence"

The United States Armed Forces are the military forces of the United States. U.S. federal law names six armed forces: the Army, Marine Corps, Navy, Air Force, Space Force, and Coast Guard. Since 1949, all of the armed forces, except the Coast Guard, have been permanently part of the United States Department of Defense, with the Space Force existing as a branch of the Air Force until 2019. They form six of the eight uniformed services of the United States.

From their inception during the American Revolutionary War, the Army and the Navy, and later the other services, have played a decisive role in the country's history. They helped forge a sense of national unity and identity through victories in the early-19th-century First and Second Barbary Wars. They played a critical role in the territorial evolution of the U.S., including the American Civil War. The National Security Act of 1947 created the Department of Defense or DoD, (after a short period being called the National Military Establishment) headed by the secretary of defense, superior to the service secretaries. It also created both the U.S. Air Force and National Security Council; in 1949, an amendment to the act merged the cabinet-level departments of the Army, Navy, and Air Force into the DoD.

The United States Air Force (USAF) is the air service branch of the United States Armed Forces. It is a part of the United States Department of Defense and is one of the six armed forces and one of the eight uniformed services of the United States. Tracing its origins to 1 August 1907, as a part of the United States Army Signal Corps, the USAF was established by transfer of personnel from the Army Air Forces with the enactment of the National Security Act of 1947. It is the second youngest branch of the United States Armed Forces and the fourth in order of precedence. The United States Air Force articulates its core missions as air supremacy, global integrated intelligence, surveillance and reconnaissance, rapid global mobility, global strike, and command and control.

The Department of the Air Force, which serves as the USAF's headquarters and executive department, is one of the three military departments of the Department of Defense. The Department of the Air Force is headed by the civilian secretary of the Air Force, who reports to the secretary of defense and is appointed by the president with Senate confirmation. The highest-ranking military officer in the Air Force is the chief of staff of the Air Force, who exercises supervision over Air Force units and serves as one of the Joint Chiefs of Staff. As directed by the secretary of defense and secretary of the Air Force, certain Air Force components are assigned to unified combatant commands. Combatant commanders are delegated operational authority of the forces assigned to them, while the secretary of the Air Force and the chief of staff of the Air Force retain administrative authority over their members.

The Department of the Army (DA) is one of the three military departments within the United States Department of Defense. The DA is the federal government agency within which the United States Army (U.S.) is organized. It is led by the secretary of the Army, a civilian official appointed by the president and confirmed by the Senate. The highest-ranking military officer in the department is the chief of staff of the Army, who is also a member of the Joint Chiefs of Staff. Other senior officials of the department are the under secretary of the Army (principal deputy to the secretary) and the vice chief of staff of the Army (principal deputy to the chief of staff.)

The DA is a successor to the Department of War which was originally formed in 1789 as an Executive Department of the United States. The Department of War was split by the National Security Act of 1947 into the Department of the Army and Department of the Air Force on September 18, 1947.

The United States Department of the Navy (DON) is one of the three military departments within the United States Department of Defense. It was established by an Act of Congress on 30 April 1798, at the urging of Secretary of War James McHenry, to provide a government organizational structure to the United States Navy (USN). Since 1834, the department has exercised jurisdiction over the United States Marine Corps (USMC), and during wartime the United States Coast Guard (USCG). These branches remain at all times independent and coequal service branches within the DON. It is led by the secretary of the Navy (SECNAV), a statutory civilian officer.

The Department of the Navy was an executive department, whose secretary served on the president's cabinet, until 1949, when amendments to the National Security Act of 1947 established the Department of Defense as a unified department for all military services; the DON, along with the Department of the Army and Department of the Air Force, became a component of the DoD, subject to the authority, direction and control of the secretary of defense.

The United States Department of the Air Force (DAF) is one of the three military departments within the Department of Defense of the United States of America. The Department of the Air Force was formed on September 18, 1947, per the National Security Act of 1947 (codified into Title 10 of the United States Code) and it is the military department within which the United States Air Force and the United States Space Force are organized.

The Department of the Air Force is headed by the secretary of the Air Force (SAF/OS), a civilian, who has the authority to conduct all of its affairs, subject to the authority, direction and control of the secretary of defense. The secretary of the Air Force's principal deputy is the under secretary of the Air Force (SAF/US). Their senior staff assistants in the Office of the Secretary of the Air Force are five assistant secretaries for acquisition, technology & logistics; financial management & comptroller; installations, environment & energy; manpower & reserve affairs; and space acquisition & integration and a general counsel. The highest-ranking military officers in the department, and senior military advisers to the secretary, are the chief of staff of the Air Force and chief of space operations.