A unified combatant command, also referred to as a combatant command (CCMD), is a joint military command of the United States Department of Defense that is composed of units from two or more service branches of the United States Armed Forces, and conducts broad and continuing missions. There are currently 11 unified combatant commands, and each is established as the highest echelon of military commands, in order to provide effective command and control of all U.S. military forces, regardless of branch of service, during peace or during war time. Unified combatant commands are organized either on a geographical basis (known as an "area of responsibility", AOR) or on a functional basis, e.g., special operations, force projection, transport, and cybersecurity. Currently, seven combatant commands are designated as geographical, and four are designated as functional. Unified combatant commands are "joint" commands and have specific badges denoting their affiliation.
The Unified Command Plan (UCP) establishes the missions, command responsibilities, and geographic areas of responsibility of the combatant commands. Each time the Unified Command Plan is updated, the organization of the combatant commands is reviewed for military efficiency and efficacy, as well as alignment with national policy.
Each unified combatant command is led by a combatant commander (CCDR), who is a four-star general or admiral. The combatant commanders are entrusted with a specific type of nontransferable operational command authority over assigned forces, regardless of branch of service. The chain of command for operational purposes (per the Goldwater–Nichols Act) goes from the president of the United States through the secretary of defense to the combatant commanders.
Command authority
Four types of command authority can be distinguished:
COCOM – combatant command: unitary control not further delegatable by the combatant commander (CCDR) ADCON - administrative control of the command function of "obtaining resources, direction for training, methods of morale and discipline" OPCON - operational control of a command function, e.g. sustainment. In that case, OPCON is embodied in the Army Field Support Brigades (AFSBs) TACON - tactical control of sustainment, for example as embodied in a Contracting Support Brigade
List of combatant commands
‡ Currently, four geographic combatant commands have their headquarters located outside their geographic area of responsibility.
History
The current system of unified commands in the U.S. military emerged during World War II with the establishment of geographic theaters of operation composed of forces from multiple service branches that reported to a single commander who was supported by a joint staff. A unified command structure also existed to coordinate British and U.S. military forces operating under the Combined Chiefs of Staff, which was composed of the British Chiefs of Staff Committee and the U.S. Joint Chiefs of Staff.
World War II era
In the European Theater, Allied military forces fell under the command of the Supreme Headquarters Allied Expeditionary Force (SHAEF). After SHAEF was dissolved at the end of the war, the American forces were unified under a single command, the US Forces, European Theater (USFET), commanded by General of the Army Dwight D. Eisenhower. A truly unified command for the Pacific War proved more difficult to organize, as neither General of the Army Douglas MacArthur nor Fleet Admiral Chester W. Nimitz was willing to be subordinate to the other, for reasons of interservice rivalry.
The Joint Chiefs of Staff continued to advocate in favor of establishing permanent unified commands, and President Harry S. Truman approved the first plan on 14 December 1946. Known as the "Outline Command Plan", it would become the first in a series of Unified Command Plans. The original "Outline Command Plan" of 1946 established seven unified commands: Far East Command, Pacific Command, Alaskan Command, Northeast Command, the U.S. Atlantic Fleet, Caribbean Command, and European Command. However, on 5 August 1947, the CNO recommended instead that CINCLANTFLT be established as a fully unified commander under the broader title of Commander in Chief, Atlantic (CINCLANT). The Army and Air Force objected, and CINCLANTFLT was activated as a unified command on 1 November 1947. A few days later, the CNO renewed his suggestion for the establishment of a unified Atlantic Command. This time his colleagues withdrew their objections, and on 1 December 1947, the U.S. Atlantic Command (LANTCOM) was created under the Commander in Chief, Atlantic (CINCLANT).