With great power comes great responsibility, as Uncle Ben told Peter Parker long ago. This doctrine became a great burden for Spider-man, yet also helped him become the super-hero we all (except for a certain JJJ the third) love.
But one problem that plagued Spidey also plagues the US--just because one is responsible for using one's power well, does not mean that one is responsible for everything that happens. The current debate is about Iraq and the rest of the Mideast--that whatever is going wrong is the fault of the U.S. Maybe so, maybe not. But the thing to consider now is whether American action would actually make things better or worse.
Consider Fallujah. Arguing about who "lost" Fallujah is, of course, silly since it is still there on the map. We know where it is. It was never in the US's pocket or safe. It was and is always in Iraq, which means that when the US left Iraq (which was the responsible thing to do, given what the Iraqis would not allow and what the American people would no longer support), it would not be able to lose it. There is only so much the US can do about anything.
Consider Syria. Yes, things are awful there. It is not clear that an American invasion would make things much better given the instructive example of .... Iraq.
I do not want to diminish the responsibility of the US in the variety of Mideast messes due to past actions and past inactions. Invading Iraq has created a cascade of stuff that cannot be undone. However, making the US responsible for everything means making everyone else far less responsible, and it exaggerates the ability of the US to change things now.
With great power comes great responsibility but not great control over anything. Tis frustrating but unavoidable.