(n) the government agency in the United Kingdom that is responsible for internal security and counterintelligence on British territory, Syn. MI, Military Intelligence Section 5
(n) the internal counterintelligence agency of the Russian Federation and successor to the Soviet KGB; formerly led by Vladimir Putin, Syn. Federal Security Service, FSB
(n) the Israeli domestic counterintelligence and internal security agency, Syn. General Security Services, Example:the Shin Bet also handles overall security for Israel's national airline