Armenia had a CSTO guarantee. Nagorno-Karabakh did not.
During the six-week 2020 war, Azerbaijan fought to recover territory internationally recognised as Azerbaijani. Armenia belonged to the Russia-led CSTO, but the alliance’s collective-defence commitments did not officially extend to Nagorno-Karabakh.
Armenia had a collective-defence alliance. The 2020 war took place largely outside the territory that alliance promised to defend.
The autumn 2020 conflict was a six-week war between Azerbaijan and Armenian and Nagorno-Karabakh forces. The Congressional Research Service describes Nagorno-Karabakh and the surrounding territories as internationally recognised parts of Azerbaijan. Azerbaijan recovered much of the territory it had lost in the fighting of the 1990s, including surrounding districts and part of Nagorno-Karabakh.
Armenia was not an isolated state. It and Russia belonged to the Collective Security Treaty Organization, the Russia-led alliance whose members commit to defend one another’s territorial integrity in the event of aggression. Russia also had a bilateral security relationship with Armenia and a military base at Gyumri. Those facts explain why Armenians expected Moscow and the CSTO to matter when the war began.
They did not, however, make every Armenian-linked battlefield an attack on Armenia. The same Congressional Research Service report says the CSTO and bilateral commitments did not officially extend to Nagorno-Karabakh. The International Crisis Group’s reporting on the post-war region describes Russia as Armenia’s treaty ally and the mediator that brokered the 2020 ceasefire, while treating the enclave as a separate and disputed theatre.
The alliance could therefore remain real in Armenia without producing collective combat intervention for Nagorno-Karabakh. Armenia treated the enclave’s population and territory as central to its security. The treaty question, however, turned on the borders of a member state.
Moscow brokered the November ceasefire and deployed roughly 2,000 peacekeepers to the conflict zone, including a role securing the corridor linking Armenia to Nagorno-Karabakh. That intervention did not convert the CSTO into a guarantee of the enclave’s political status. The retrieved reporting establishes a limit on treaty scope, not that Russia abandoned Armenia in every respect.
AI-generated representative image.