International affairs is very much run like the mafia. The godfather does not accept disobedience, even from a small storekeeper who doesn't pay his protection money. You have to have obedience otherwise the idea can spread that you don't have to listen to the orders and it can spread to important places.
I think Jonah Goldberg would agree:
Well, I've long been an admirer of, if not a full-fledged subscriber to, what I call the "Ledeen Doctrine."... "Every ten years or so, the United States needs to pick up some small crappy little country and throw it against the wall, just to show the world we mean business."