Here are the Russian allies who are most likely to side with President Putin if he starts a conflict in Ukraine.
The Collective Security Treaty Organisation (CSTO) acts a bit like NATO. It is formed of former soviet states and is effectively a security pact.
The six countries who make up the CSTO (Russia, Armenia, Belarus, Kazakhstan, Kyrgyzstan and Tajikistan) will likely come to each other’s defence if attacked.
Although the organisation isn’t supposed to deal with domestic disputes, some or all of these allies would likely come to President Putin’s aid in the event of a large-scale war that could be triggered if Russia invades Ukraine.