I don't think he would and it would be the right thing. As a leader you must take care of your own first. Basically if I was American president I would let the Europe burn in order to save even the shittiest city in USA, and of course the same principle would apply if I were a leader in an European country. Alliance and relations with other nations is a good thing but leaders have a duty to protect their own first.
With an attitude like that the enemy will move his position further one step at a time until you no longer is in a position to defend yourself.
Since Im in the mood of quoting people today, Reagan put it very well in one of his earliest speeches.
Every lesson in history tells us that the greater risk lies in appeasement, a policy of accommodation is appeasement, and it gives no choice between peace and war, only between fight and surrender. If we continue to accommodate, continue to back and retreat, eventually we have to face the final demand--the ultimatum. And what then? When Nikita Khrushchev has told his people he knows what our answer will be? He has told them that we are retreating under the pressure of the Cold War, and someday when the time comes to deliver the ultimatum, our surrender will be voluntary because by that time we will have weakened from within spiritually, morally, and economically. He believes this because from our side he has heard voices pleading for "peace at any price" or "better Red than dead," or as one commentator put it, he would rather "live on his knees than die on his feet." And therein lies the road to war, because those voices don't speak for the rest of us. You and I know and do not believe that life is so dear and peace so sweet as to be purchased at the price of chains and slavery. Where, then, is the road to peace? Well, it's a simple answer after all.
You and I have the courage to say to our enemies, "There is a price we will not pay." There is a point beyond which they must not advance.