Russian President Vladimir Putin and Armenian Prime Minister Nikol Pashinyan in Kazakhstan in October 2022.Dmitry Azarov/AP PhotoArmenia's prime minister said he's taking his country out of the Collective Security Treaty Organization.The CSTO, a military alliance of post-Soviet states, is considered Putin's answer to NATO.But tensions have been growing, and this is only the latest clash among Russia's supposed allies.A key Russian ally said it is quitting the Collective Security Treaty Organization, a group widely considered to be President Vladimir Putin's answer to NATO.Armenia's Prime Minister Nikol Pashinyan, who has repeatedly snubbed Russia, said in parliament on Wednesday that he will take his country out of the Moscow-led CSTO alliance, the Associated Press reported.Pashinyan said his government would decide later when to make the move, according to the AP.Experts previously told Business Insider that Putin founded the alliance — made up of Russia, Armenia, Kazakhstan, Belarus, Kyrgyzstan, and Tajikistan — as a rival to NATO, and that he wanted to project power by leading a multinational body, despite most of the members not having notable militaries or large economies.However, the plan seems to have backfired as tensions among the alliance have grown, especially since Russia launched its full-scale invasion of Ukraine in February 2022.Pashinyan's latest announcement is likely a huge blow to Putin.Pashinyan told lawmakers: "We will leave.