Wikipedia
Counter-Guerrilla is the Turkish branch of Operation Gladio, a clandestine stay-behind anti-communist initiative backed by the United States as an expression of the Truman Doctrine. The founding goal of the operation was to erect a guerrilla force capable of countering a possible Soviet invasion. The goal was soon expanded to subverting communism in Turkey.
The Counter-Guerrilla initially operated out of the Turkish Armed Forces' Tactical Mobilization Group (, or STK). In 1967, the STK was renamed to the Special Warfare Department (, ÖHD). In 1994, the ÖHD became the Special Forces Command (, ÖKK).
In Turkey there is a popular belief that the Counter-Guerrilla are responsible for numerous unsolved acts of violence, and have exerted great influence over the country's Cold War history, most notably for engendering the military coups of 1971 and 1980.
The military accepts that the ÖKK is tasked with subverting a possible invasion, though it denies that the unit is Gladio's "Counter-Guerrilla", i.e., that it has engaged in " Black Operations". After the dissolution of the Soviet Union, the Counter-Guerrilla were used to fight the militant PKK (cf. Susurluk scandal), which has since its inception been regarded as a major threat.
Counter-Guerilla's existence was revealed in 1971 by survivors of the Ziverbey incident, and officially on 26 September 1973 by prime minister Bülent Ecevit. Twenty days later he was shot at; he survived. The next prime minister who openly talked about such matters, Turgut Özal, also narrowly evaded an assassination attempt. The subject has been broached by parliament at least 27 times since 1990, however no successful investigation has taken place. Deputies of the incumbent party in any given administration always voted in dissent.