Well, considering that most of the NATO countries in Europe have been reliant on US funding for decades to prop up their poorly equipped "armies," what few they have, and considering that America is currently under leadership that doesn't even know how to protect our own people much less anyone else? I'd wager right and properly fucked. If Russia wants they don't even have to fire a shot at Europe, they can choke off resources at a rate and scale the US wouldn't be able to offset after crippling our own energy production and manufacturing/production capabilities. If the Russians do decide to spread militarily through Europe, I'm sure some of the smaller Baltic countries would put up a hell of a fight just out of sheer hatred. Western Europe is fucked for the most part, the UK could probably fair alright and even the Ruskies probably know not to try Switzerland. But most of them would probably capitulate anyway because if most Americans don't want to die for Ukraine or Bidens blunders, why should anyone else?