for Russia the stakes are existential
No. For Ukraine the stakes are existential. Not Russia.
Russia is invading Ukraine.
You're talking about communist utopia kind of world.
In real world, there are only select few countries with UN veto power, and they play by different rules.
USA didn't see Russia as partner after collapse of Soviet Union, but as defeated side in cold war.
We're not looking at consequences, as Russia doesn't seem willing to play that role