Countries should be left to handle their own affairs; that's the responsibility that is inherent to sovereignty. The premise of a global hegemon who babysits the world and enforces the rules (dictated by themselves and their allies of course) is an anachronistic leftover from the age of imperialism. If the rest of the world wants America to play world police (and for the most part, I don't believe they do) let them pay the American public for this service.