Collective Security Treaty Organization

Background

The Collective Security Treaty Organization is an intergovernmental military alliance in Eurasia made up of six post-Soviet states: Armenia, Belarus, Kazakhstan, Kyrgyzstan, Russia, and Tajikistan. Its core mandate is collective defense and security cooperation among member states, with Article 4 of the Collective Security Treaty stating that aggression against one signatory is treated as aggression against all. The organization matters because it provides a formal regional security framework linking the armed forces and defense policies of its members, and it also includes commitments by signatories to refrain from the use or threat of force against one another.

The organization operates through shared intergovernmental institutions rather than as a standing national military body. Its members coordinate policy under the CSTO charter, which was adopted in 2002 and reaffirmed the goal of avoiding conflict between participating states. Russia is one of the principal member states and a central participant in the alliance, alongside Belarus and the other Eurasian members. The CSTO also restricts members from joining other military alliances, making it a significant part of the security architecture of the participating states.

The CSTO grew out of the post-Soviet security environment that followed the dissolution of the Soviet Armed Forces, which were replaced in 1992 by the United Armed Forces of the Commonwealth of Independent States and then by the successor armed forces of independent states. The collective security treaty later became the basis for the present organization, while several states that had previously belonged to the alliance, including Azerbaijan, Georgia, and Uzbekistan, later withdrew. In recent years, the CSTO has remained a relevant forum for security coordination among its members, especially in relation to regional defense cooperation and collective responses to threats in the post-Soviet space.