Direct action (military) in the context of "Lithuanian Special Operations Force"

Special forces or special operations forces (SOF) are military units trained to conduct special operations. NATO has defined special operations as "military activities conducted by specially designated, organized, selected, trained and equipped forces using unconventional techniques and modes of employment".

Special forces emerged in the early 20th century, with a significant growth in the field during World War II, when "every major army involved in the fighting" created formations devoted to special operations behind enemy lines. Depending on the country, special forces may perform functions including airborne operations, counter-insurgency, counter-terrorism, foreign internal defense, covert ops, direct action, hostage rescue, high-value targets/manhunt, intelligence operations, mobility operations, and unconventional warfare.

The 1st Special Forces Operational Detachment–Delta (1st SFOD-D), also known as Delta Force, Combat Applications Group (CAG), or within Joint Special Operations Command (JSOC) as Task Force Green, is a special operations force of the United States Army under the operational control of JSOC. The unit's missions primarily involve counterterrorism, hostage rescue, direct action, and special reconnaissance, often against high-value targets.

Delta Force, along with the Intelligence Support Activity, and its Navy and Air Force counterparts, DEVGRU (SEAL Team 6) and the 24th Special Tactics Squadron, are the U.S. military's tier one special mission units that are tasked with performing the most complex, covert, and dangerous missions directed by the president of the United States and the secretary of defense.

The United States Army Special Forces (SF), colloquially known as the "Green Berets" due to their distinctive service headgear, is a branch of the United States Army Special Operations Command (USASOC).

The core missionset of Special Forces contains five doctrinal missions: unconventional warfare, foreign internal defense, direct action, counterterrorism, and special reconnaissance. The unit emphasizes language, cultural, and training skills in working with foreign troops; recruits are required to learn a foreign language as part of their training and must maintain knowledge of the political, economic, and cultural complexities of the regions in which they are deployed. Other Special Forces missions, known as secondary missions, include combat search and rescue (CSAR), counter-narcotics, hostage rescue, humanitarian assistance, humanitarian demining, peacekeeping, and manhunts. Other components of the United States Special Operations Command (USSOCOM) or other U.S. government activities may also specialize in these secondary missions. The Special Forces conduct these missions via five active duty groups, each with a geographic specialization; and two National Guard groups that share multiple geographic areas of responsibility. Many of their operational techniques are classified, but some nonfiction works and doctrinal manuals are available.

Special reconnaissance (SR) is conducted by small units, such as a recon team, made up of highly trained military personnel, usually from special forces units and/or military intelligence organizations. Special reconnaissance teams operate behind enemy lines, avoiding direct combat and detection by the enemy. As a role, SR is distinct from commando operations, but both are often carried out by the same units. The SR role frequently includes covert direction of airstrikes and indirect fire, in areas deep behind enemy lines, placement of remotely monitored sensors, and preparations for other special forces. Like other special forces, SR units may also carry out direct action and unconventional warfare, including guerrilla operations.

In intelligence terms, SR is a human intelligence (HUMINT) collection discipline. Its operational control is likely to be inside a compartmented cell of the HUMINT, or possibly the operations, staff functions. Since such personnel are trained for intelligence collection as well as other missions, they will usually maintain clandestine communications to the HUMINT organization and will be systematically prepared for debriefing. They operate significantly farther forward than even the most forward friendly scouting and surveillance units.

The Special Air Service (SAS) is a special forces unit of the British Army. It was founded as a regiment in 1941 by David Stirling, and in 1950 it was reconstituted as a corps. The unit specialises in a number of roles including counter-terrorism, hostage rescue, direct action and special reconnaissance. Much of the information about the SAS is highly classified, and the unit is not commented on by either the British government or the Ministry of Defence due to the secrecy and sensitivity of its operations.

The corps consists of the 22 Special Air Service Regiment, which is the regular component, as well as the 21 Special Air Service Regiment (Artists) (Reserve) and the 23 Special Air Service Regiment (Reserve), which are reserve units, all under the operational command of United Kingdom Special Forces (UKSF). Its sister unit is the Royal Navy's Special Boat Service, which specialises in maritime counter-terrorism. Both units are under the operational control of the Director Special Forces.