United States Army Special Forces

The United States Army Special Forces Known as "Green Berets" because of their distinctive service headgear are a special operations force of the United States Army that is designed to deploy and execute nine doctrinal missions: unconventional warfare, foreign internal defence, direct action, counter-insurgency, special reconnaissance, counter-terrorism, information operations, counter-drug operations, and counter-proliferation. It is important to have linguistic, cultural, and training capabilities while dealing with foreign soldiers in the first two missions: unconventional warfare and foreign internal defences. Another kind of Special Forces mission is combat search and rescue (CSAR), which includes hostage rescue, humanitarian aid, humanitarian demining and information operations. Other types of Special Forces missions include peacekeeping missions and manhunts. It is possible that additional elements of the United States Special Operations Command (USSOCOM) or other United States government operations will specialise in these supplementary tasks. These operations are carried out by seven regionally concentrated units of Special Forces personnel. Some factual books and doctrinal documents about their operating methods are accessible, but many of their operational techniques are classified.

Special Forces, as special operations forces, are not always under the command authority of the field commanders of the nations in which they operate on the ground. While in theatre, SF forces may report directly to a geographic combatant command, USSOCOM, or other command authority, rather than to a higher-level headquarters. The Special Activities Center (previously known as the "Special Activities Division") of the Central Intelligence Agency (CIA), and more particularly its Special Operations Group (SOG), draws its personnel from the United States Army's Special Forces. It was during the Vietnam War that the CIA and the Army Special Forces first collaborated on joint operations. The spirit of collaboration is still alive and well today, as shown by the War in Afghan.