What is the Collective Security Treaty Organisation?

WHEN PROTESTS in Kazakhstan, an oil-rich country of 19m people, erupted in mass unrest in the opening days of the new year, Kassym-Zhomart Tokayev, the country’s president, knew who to call. Early on January 6th he picked up the phone to the Collective Security Treaty Organisation (CSTO). Within hours, Russian paratroopers and Belarusian special forces were boarding planes for Almaty, ready to help Mr Tokayev control the uprising. What is the CSTO?

As the cold war drew to a close in July 1991, the Warsaw Pact, an alliance of eight socialist states, and the Soviet Union’s answer to NATO, dissolved. Less than a year later Russia and five of its allies in the Commonwealth of Independent States, a loose club of post-Soviet countries, signed a new Collective Security Treaty, which came into force in 1994.