Combatant commander in the context of "Special operations"

The United States Army (U.S. Army) is the land service branch of the United States Armed Forces. It is designated as the Army of the United States in the United States Constitution. It operates under the authority, direction, and control of the United States secretary of defense. As a part of the United States Department of Defense, it is one of the six armed forces of the United States and one of the eight uniformed services of the United States. The Army is the most senior branch in order of precedence amongst the armed services. It has its roots in the Continental Army, formed on 14 June 1775 to fight against the British for independence during the American Revolutionary War (1775–1783). After the Revolutionary War, the Congress of the Confederation created the United States Army on 3 June 1784 to replace the disbanded Continental Army.

The U.S. Army is part of the Department of the Army, which is one of the three military departments of the Department of Defense. The U.S. Army is headed by a civilian senior appointed civil servant, the secretary of the Army (SECARMY), and by a chief military officer, the chief of staff of the Army (CSA) who is a member of the Joint Chiefs of Staff. It is the largest military branch, and in the fiscal year 2022, the projected end strength for the Regular Army (USA) was 480,893 soldiers; the Army National Guard (ARNG) had 336,129 soldiers and the U.S. Army Reserve (USAR) had 188,703 soldiers; the combined-component strength of the U.S. Army was 1,005,725 soldiers. The Army's mission is "to fight and win our Nation's wars, by providing prompt, sustained land dominance, across the full range of military operations and the spectrum of conflict, in support of combatant commanders". The branch participates in conflicts worldwide and is the major ground-based offensive and defensive force of the United States of America.‌

The Supreme Allied Commander Europe (SACEUR) is the commander of the North Atlantic Treaty Organization's (NATO) Allied Command Operations (ACO) and head of ACO's headquarters, Supreme Headquarters Allied Powers Europe (SHAPE). The commander is based at SHAPE in Casteau, Belgium. In effect, SACEUR is the second-highest military position within NATO, below only the Chair of the NATO Military Committee in terms of precedence. There is another Supreme Allied Commander in NATO, Supreme Allied Commander Transformation (SACT), titularly equal, but whose duties are less operational. SACT, in Norfolk, Virginia, has responsibility for capability development rather than operations.

SACEUR has always been held by a U.S. military officer, and the position is dual-hatted with that of Commander of United States European Command.

The Goldwater–Nichols Department of Defense Reorganization Act of October 4, 1986 (Pub. L. 99–433; signed by President Ronald Reagan) made the most sweeping changes to the United States Department of Defense since the department was established in the National Security Act of 1947 by reworking the command structure of the U.S. military. It increased the powers of the chairman of the Joint Chiefs of Staff and implemented some of the suggestions from the Packard Commission, commissioned by President Reagan in 1985. Among other changes, Goldwater–Nichols streamlined the military chain of command, which now runs from the president through the secretary of defense directly to combatant commanders (CCDRs, all four-star generals or admirals), bypassing the service chiefs. The service chiefs were assigned to an advisory role to the president and the secretary of defense, and given the responsibility for training and equipping personnel for the unified combatant commands.

Named after Senator Barry Goldwater (R-Arizona) and Representative Bill Nichols (D-Alabama), the bill passed the House of Representatives, 383–27, and the Senate, 95–0. It was signed into law by President Reagan on October 1, 1986. Admiral William J. Crowe was the first chairman to serve under this new legislation.

Area of responsibility (AOR) is a pre-defined geographic region assigned to Combatant commanders of the Unified Command Plan (UCP), that are used to define an area with specific geographic boundaries where they have the authority to plan and conduct operations; for which a force, or component commander bears a certain responsibility. The term may also be used in other countries worldwide but it originated within the United States Armed Forces. This system is designed to allow a single commander to exercise command and control of all military forces in the AOR, regardless of their branch of service.

George W. Bush signed the U.S. Unified Command Plan (UCP) 2008 on 17 December 2008, establishing the up-to-date boundaries for the newest Command, United States Africa Command (USAFRICOM), and all changes to boundaries of the other Commands.