I have many moral problems with that scenario. I used to live in the US a long time ago. The US is sick; there's a mad king at the top who doesn't have the well being of the nation in his interest, and he is driving the world towards war with every passing day while dividing his own people. War with the US isn't a clear cut "good vs evil" situation as the EU vs russia would be, it would be a utter tragedy, not wanted by neither the populace of the EU, nor the US.
That said, yes, I would defend Europe against the US, even though I think that fight would be short, deadly and decisive if it really came down to it.
What a fucked up world we live in, just because idiots voted for a convicted felon.
> War with the US isn't a clear cut "good vs evil" situation as the EU vs russia would be
I don't think EU vs Russia would be a "good vs evil" situation. Russia/US seem pretty similar to me, dictatorship/propaganda with a majority of the population being regular people not in favor of any war, and 30% of indoctrinated people.
You seem to have very little contact to Russians living in Russia or Germany. Their version of "not in favor of any war" is a very strange one – it's more a stance of indifference than disfavor.
I don't know why you believe that a decades-long strict dictatorship like Russia has more democratic support for its "evil" government than a country whose leader was elected just 1 year ago with approximately 50% of the vote.
Russians are lining up to go to war under the promise of money, around 30k a month last time I checked. Americans not so much, in particular not against Europeans. It's different in my view.
Americans don't need money to fight. I was paid $0 with the YPG and had to bankroll my own time. Lots of Americans there. I met a lot of them that didn't even really give a shit about the sides of the war, they just needed to fight something. We're a savage people.
Which historically has worked more for us, than against us.