Collective Security Treaty Organization

Security · CSTO

The six governments here all answered to Moscow until 1991. The Collective Security Treaty they signed at Tashkent on 15 May 1992 has eleven articles in it. Article 4 treats armed aggression against one party as aggression against all of them. Collective forces have been deployed under it once, to Kazakhstan on 6 January 2022, and withdrawn by 19 January.

Questions about CSTO

Which countries are in the CSTO?

The 6 parties to the Collective Security Treaty are Armenia, Belarus, Kazakhstan, Kyrgyzstan, Russia and Tajikistan, and they are listed on this page. Armenia, Kazakhstan, Kyrgyzstan, Russia and Tajikistan signed the treaty at Tashkent on 15 May 1992. Belarus acceded in 1993.

What does Article 4 say, and has it ever been used?

It provides that aggression against one party is to be regarded as aggression against all of them, and that the others will then give the assistance needed, military assistance included, at the request of the party attacked. It has produced one deployment. The Collective Security Council decided on 6 January 2022 to send the Collective Peacekeeping Forces to Kazakhstan, and the withdrawal was completed on 19 January 2022.

Has any country left the CSTO?

Azerbaijan and Georgia acceded in 1993 and ceased to be parties on 2 April 1999, when they did not sign the protocol prolonging the treaty. Uzbekistan signed the original text at Tashkent in 1992, did not sign the protocol of 1999, returned in the summer of 2006 and suspended its membership in 2012. Article 11 sets the exit at six months of written notice, with outstanding obligations settled first.

Is Armenia still a member of the CSTO?

It is still a party to the treaty and it has frozen its participation. A statement of 23 February 2024 announced the freeze, and in May 2024 Armenia said it would not pay into the budget. No notice of withdrawal under Article 11 has been given. This catalogue records both facts and takes no position on which of them settles the question.

Can a CSTO member belong to other alliances?

Article 1 bars a party from joining alliances or groupings of states directed against another party, and nothing wider than that. Every member also belongs to the Commonwealth of Independent States and to the OSCE. Five are in the Eurasian Economic Union, four in the Shanghai Cooperation Organisation, and Armenia in the Council of Europe.

How does a state join the CSTO?

The Charter of 7 October 2002 opens the organisation to any state that shares its goals and principles, and admission is decided by the Collective Security Council, where every decision other than a procedural one is taken by consensus and each member has one vote. No state has acceded since Uzbekistan returned in 2006.

Sources

Collective Security Treaty of May 15, 1992 · Collective Security Treaty Organization. The English text of the eleven articles, including Article 1, Article 4 and the term and exit in Article 11.
Charter of the Collective Security Treaty Organization · Collective Security Treaty Organization. The bodies, the one vote for each member, the consensus rule, the Moscow seat and the terms of admission and withdrawal.
From the Treaty to the Organization · Collective Security Treaty Organization. The signature at Tashkent, the accessions of 1993, the entry into force on 20 April 1994, the Chisinau charter and the Uzbek return and suspension.
Statement of treaties and international agreements, December 2003 · United Nations Treaty Section. The Charter done at Chisinau on 7 October 2002, entry into force on 18 September 2003 in accordance with article 26, and its registration.
About CSTO Cooperation with the UN · Collective Security Treaty Organization. Observer status in the General Assembly under resolution 59/50 of 2 December 2004.
Collective Security Treaty Organization · Ministry of Foreign Affairs of the Republic of Belarus. The protocol prolonging the treaty signed in April 1999 by six of the nine parties, and not by Azerbaijan, Georgia or Uzbekistan.
Collective Security Treaty Organisation (CSTO) · President of Russia, reference entry. The protocol of 2 April 1999 and the three governments that declined the prolongation.
Session of the Collective Security Council, 2009 · Collective Security Treaty Organization. The agreement on the Collective Rapid Reaction Force signed at the Moscow session of 14 June 2009.
Contingents of the CSTO Collective Peacekeeping Forces are deployed to the Republic of Kazakhstan · Collective Security Treaty Organization, 6 January 2022. The decision of the Collective Security Council, the contributing countries and the stated tasks.
CSTO Peacekeepers Complete Their Mission, Withdraw from Kazakhstan · The Astana Times. The completion of the withdrawal on 19 January 2022.
Extraordinary session of the CSTO Collective Security Council on the situation on the Armenian border · Collective Security Treaty Organization, 13 September 2022. The session called at Armenia's initiative, the political and diplomatic settlement agreed and the mission sent to report back.
Armenia freezes participation in Russia-led security bloc · Reuters, 23 February 2024. The announcement of the freeze, and the refusal of the following May to fund the budget.