A longtime Russia ally suspended participation in Putin's NATO rival after calling it ineffective

• Armenia said it has "in practical terms frozen our participation" in the Russian-led CSTO.
• Russia wanted the CSTO to be a NATO equivalent, but in recent years it has been crumbling.
• Armenia is a longtime Russian ally but it has been openly critical and has forged new Western ties.

Armenia, formally a key ally of Russia, has suspended its participation in a Russia-led international alliance, according to its prime minister, Nikol Pashinyan.

The Collective Security Treaty Organization, or CSTO, is considered Russia's equivalent to NATO, and Russian President Vladimir Putin hoped it could rival the Western military alliance.

But splinters have emerged in the group since Russia invaded Ukraine, and Armenia has repeatedly challenged its usefulness.

Pashinyan spoke with France24 last week about the CSTO, where he said: "The Collective Security Treaty has not fulfilled its objectives as far as Armenia is concerned, particularly in 2021 and 2022. And we could not let that happen without taking notice."

"We have now in practical terms frozen our participation in this treaty. As for what comes next, we shall have to see," he said, per Reuters reporting.

The Kremlin said on Friday that it had not received official confirmation that Armenia was leaving the alliance, but that it was seeking clarification, The Moscow Times reported.

Pashinyan has frequently expressed frustration with Russia and the CSTO in recent years, accusing the alliance of being ineffective and describing Armenia as no longer an ally of Russia.

Even so, this latest development is a significant one: The countries have long-standing ties, and Armenia was once part of the Soviet Union.

The move also comes as Russia is further isolated from much of the world, following its full-scale invasion of Ukraine, and is looking to its old allies for support.

Tensions became visible in 2022, when Armenia called on the CSTO for help during border clashes with neighboring Azerbaijan. Russia did not send troops, infuriating the country's leadership.

Pashinyan called the response "depressing" and "hugely damaging to the CSTO's image both in our country and abroad."

He then physically distanced himself from Putin in a group photo at an international summit in November 2022.

Months later, Pashinyan said that Armenia could leave the CSTO if its benefits to his country weren't proven.

More snubs followed. Pashinyan canceled military drills with Russia in January 2023, and in September Armenia announced a joint military exercise with the US.

Pashinyan said in June that his country was "not Russia's ally in the war with Ukraine" and said it felt trapped in the middle between Russia and the West.

Armenia also ordered air-defense systems and radars from France last year. An expert told Business Insider that this showed how Armenia wants to build security ties outside of Eurasia.

Pashinyan's criticism deepened as Armenia's security concerns grew last year over fighting in the long-disputed territory of Nagorno-Karabakh. Azerbaijan took control of the territory, driving out thousands of ethnic Armenians.

Frustrations with Russia have also risen among other CSTO members, experts told Business Insider last year.

Russia's invasion of Ukraine, as well as its performance in the war, has sparked doubts in those countries over whether Russia could protect them, or indeed whether they will be safe from Russia itself in the future, the experts said.

But Russia has not been left alone on the world stage: It has deepened cooperation with Iran and North Korea since it started its full-scale invasion, and China has continued to give financial support.

The countries turning their back on it, like Armenia, are also significantly smaller and less powerful than Russia.

Even so, the snubs by CSTO members are unwelcome for Putin, who founded the alliance to project power and control, experts told Business Insider.

Jaroslava Barbieri, an expert on Russia and post-Soviet states at the University of Birmingham, told Business Insider last year that Russia's regional reputation as a security provider has been left "in tatters."

This latest news isn't going to help.