What CSTO is and how it works

What the parties signed

The Collective Security Treaty was signed at Tashkent on 15 May 1992 by Armenia, Kazakhstan, Kyrgyzstan, Russia, Tajikistan and Uzbekistan, and it runs to eleven articles. Article 1 binds the parties to abstain from the use or threat of force between themselves, and not to join alliances or groupings of states directed against another party. Article 2 provides for immediate joint consultation whenever a party's security, territorial integrity or sovereignty is threatened. Article 4 is the clause the organisation is named for: aggression against one party is to be regarded as aggression against all of them, and the others are then to give the necessary assistance, military assistance included, at the request of the party attacked, in exercise of the right of collective defence under Article 51 of the United Nations Charter.

Article 11 fixes the term and the exit. The treaty was concluded for five years with prolongation, instruments of ratification go to the depositary, and a party leaving gives written notice six months in advance and settles its obligations first.

Belarus was not at Tashkent. It acceded in 1993, along with Azerbaijan and Georgia, and it is the one current party that did not sign the original text.

The treaty and the organisation are not the same instrument

The treaty entered into force on 20 April 1994, once ratification was complete in every capital. Eight years later the parties gave it an institution. The Charter of the Collective Security Treaty Organization was done at Chisinau on 7 October 2002 and entered into force on 18 September 2003 in accordance with its Article 26, and it is registered in the United Nations Treaty Series at volume 2235.

The Charter creates a Collective Security Council above councils of foreign ministers, of defence ministers and of secretaries of security councils, with a Permanent Council, a Secretariat and a Joint Staff beneath them. Each member state has one vote, and every decision other than a procedural one is taken by consensus, so nothing is put to a majority and no member is outvoted. The Secretariat sits in Moscow. The General Assembly granted the organisation observer status by resolution 59/50 of 2 December 2004.

Who left, and who came back

The five-year term made 1999 a decision point. Six governments signed the protocol prolonging the treaty at Moscow on 2 April 1999: Armenia, Belarus, Kazakhstan, Kyrgyzstan, Russia and Tajikistan, which is the present roster exactly. Azerbaijan, Georgia and Uzbekistan did not sign it and ceased to be parties. Uzbekistan returned in the summer of 2006 and suspended its membership in 2012, and the roster has stood as it is since.

Accession is open on the Charter's terms to any state that shares the goals and principles of the organisation, on a decision of the Collective Security Council. Nobody has taken that route since 2006.

What has been done under it

The Collective Rapid Reaction Force was agreed at the session of the Collective Security Council held in Moscow on 14 June 2009. Belarus stayed away from that session and signed the agreement in the October following. Uzbekistan never signed it at all.

Article 4 has produced one deployment. Kazakhstan asked for assistance during the unrest of January 2022; the Collective Security Council decided on 6 January 2022 to send the Collective Peacekeeping Forces for a limited period; and contingents from Armenia, Belarus, Kyrgyzstan, Russia and Tajikistan went in with the stated task of guarding state and military installations and assisting the Kazakh authorities, not of policing the streets themselves. The withdrawal was completed on 19 January 2022. The operation lasted a fortnight, and it is the only one there has been.

What it did not do

Armenia called the other parties together on 13 September 2022, after fighting on its border with Azerbaijan. The Council met the same day, agreed that the matter should be settled by political and diplomatic means, and sent a mission of its own officials to Armenia to look at the situation and report back to the next session. No forces were sent. At that next session, held in Yerevan on 23 November 2022, Armenia declined to sign the draft declaration and the draft decision on joint measures of assistance to Armenia.

A statement of 23 February 2024 announced that Armenia had frozen its participation, and in May 2024 that it would not pay into the budget. It has not left. The notice Article 11 requires has not been given, Armenia is still a party to the treaty of 1992, and that is why this catalogue files it here. Whether a frozen participation is a membership is argued about in and around the organisation, and the catalogue records the freeze and the treaty position and settles neither.

Where else the members sign

Every member's record files it in the Commonwealth of Independent States and in the OSCE as well. Five of them are in the Eurasian Economic Union, and Tajikistan is not. Four sit in the Shanghai Cooperation Organisation, which reaches well past this group into China and South Asia. Armenia's record carries the Council of Europe, and no other member's does.

Article 1 forbids none of that. What it forbids is a party entering an alliance or a grouping directed against another party, which is a narrower rule than it is usually read as, and it is the only limit the treaty puts on where else a member may put its name.

The one member with no neighbour here

Armenia's land borders run with Azerbaijan, Georgia, Iran and Turkiye, and none of the four is a party. The other five touch: Belarus and Kazakhstan each border Russia, Kazakhstan and Tajikistan each border Kyrgyzstan. So the territory the treaty covers comes in two pieces, one of them a single country reached only across the ground of states outside the treaty, and September 2022 is where that told.