[chakhs]

Documents don't really matter in such situations. When a state believes it's in a survival fight, it doesn't care about international laws or anything, because nothing can be worse than it's death.

The US has been working on surrounding Russia with NATO states, putting bases and nuclear next to Russia, Russia tried to do the same in Cuba during the cold war but the US did not accept it and was ready to sink the Russian ships, Cuba was "free" to do that but that doesn't matter because the US beleived it's a threat. Now that Russia beleives it's strong enough to face the US on some small issues (the US is still much stronger but not as before) it no longer accepts to have NATO on it's border, especially in Ukraine because historically that's where Russians come from plus it would hurt their access to sea.

Anyways, that's how it looks like for me as a bystander.