Eastern European country sovereignty.

It gets especially absurd when Russia is in fact attacking its neighbors. Then-President Medvedev even went so far as to say Russia invaded Georgia so as to stop their ascension to NATO.

In the context of Ukraine it gets especially silly. 20% of Ukrainians wanted to join NATO before Russia invaded Ukraine in 2014. Ukraine even had explicit neutrality in its constitution at the time.

Russia has always been an imperialist bully throughout the post-Soviet independence of its neighbors.