Spetsgruppa A, aka the Alpha Group, comes to mind.
Alpha Group was created in 1972, in response to the 1972 Olympic murders, perpetrated by Islamsists. In 1985, Lebanese Islamists made the mistake of mistaking Soviet citizens for garden variety infidels ....
In October 1985 Alpha Group was tasked with a counter-terrorism hostage-rescue operation in Beirut Lebanon. Four Russian diplomats had been kidnapped there by a fundamentalist Islamic group which called itself the Islamic Liberation Organization, an offshoot of the Muslim Brotherhood. It has been speculated that this hostage-taking was revenge for Russia's support of Syria which was engaged in the shelling of Islamist militants in the Lebanese city of Tripoli. They threatened to kill the hostages one at a time unless the Soviets pressured it's ally in Damascus to put a stop to attacks on the militants in Tripoli.When Alpha arrived on the ground they found that one of the four hostages had already been shot in the head and left in a trash dump. Alpha Group quickly responded by doing something which sent a very clear and unambiguous message to those hostage-takers. Through their knowledge of who the hostage-takers were they tracked down and located one of their kinsmen and proceeded to castrate him and then send on the dismembered body parts to the hostage-takers! But not only that, with that they also sent a note indicating they knew some other relatives of the hostage-takers who could also be hurt in similar ways.
Seeing how serious the Russians were the hostage-takers promptly released these hostages -- dropping them off near the Soviet Embassy. No more Russians were taken hostage in Lebanon for another twenty years as a result of the Alpha Groups ruthlessness when it came with dealing with those people.
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