You may want to take a look at what happened the last two times the US went into isolationist mode, didn't work out well for Europe at all.
Also if you think Russia and its expansionist plans don't need keeping in check then you have no idea at all what it could mean for Europe.
Take a look at the rhetoric being used by Russian against its neighbours (all sovereign states), I can assure you that such a view will earn you no friends in Finland, Estonia, Latvia, Poland and quite a few others. However you might be right, it's not as if anything happened in Georgia, Chechnya or Crimea is it. .........oh wait.
Almost forgot,to claim that Trump is in some way anti war is absurd. Read this piece in which he refused to say he wouldn't threaten or use nukes against Europe, while telling fibs about being against the war in Iraq.
http://www.independent.co.uk/news/w...ear-weapons-in-attack-on-europe-a6961101.html