The fact remains that, since the end of World War II, Europe has conducted more than 100 armed conflicts. Several of those enlisted either the direct or indirect assistance of the US military.
The US continues to contribute Billions of dollars every year for the defense of Europeans from other Europeans. There's aren't 64,000 Americans in Europe to protect you from The Canadians.
There has to come a time when Europe either learns to settle their own problems peacefully OR continue to fight amongst yourselves but leave us out of it.