One of the most obvious benefits of having U.S. troops in Europe is its geographical proximity to some of the most dangerous and contested regions of the world. For example, when ordered to intervene in Libya, U.S. commanders in Europe were able to act effectively and promptly because of the well-established and mature U.S. military footprint in southern Europe.
They're preaching to the choir here at The Dignified Rant.
American troops are in Europe to defend our interests. Whether they allow Europeans to spend less than they would is irrelevant. Even if our withdrawal of troops prompts Europeans to replace our capabilities fully, do we really expect the Europeans to use those troops to defend our interests?
Mind you, this retreat from Europe is not a trend that started in the Obama administration. I suppose it is hoping too much that they'd be the ones to halt that trend in its tracks.