The US ruling class benefits from stability in the world since the US economy easily out-competes everyone else's. They definitely benefit from Russia's demise since Russia is causing instability in the world. They definitely don't benefit from Europeans fighting amongst themselves.

If they want stability, why do they keep doing the opposite? In Korea, Vietnam, Nicaragua, Iraq, Afghanistan, Serbia, Syria, Libya, etc. This time it just happens to be in Europe again.

Literally all those countries threatened world stability by invading their neighbours or attacking the US and others directly or indirectly.