We're not perfect by any stretch of the imagination. We've never claimed that; it's often insinuated that because we're proud of our country, we look down on other nations, which is far from the reality.
But it's a damned if you do, damned if you don't situation we're in. Our economy is crashing, we're leading peace-keeping missions abroad, we've got a situation in the ME that is tricky and not making anyone on any side happy, we're in the middle of a crisis at home, but we still donate and provide more aid abroad than most nations, we're bashed by all angles for intervening in foreign affairs yet we're still bashed for not intervening in foreign affairs, etc.
We can't win, we know this. But that isn't going to stop us from trying, and that isn't a guarantee we won't screw something up, but it's better than sitting aside and doing nothing. Until another country steps up and does something, what other viable choice do we have? (Viability being key: unilateral withdrawal and isolation are not viable; they're idealistic)