American power is an essential ingredient in the mix. But what makes that power effective, as an instrument of progressive change, is the legitimacy it gains from being deployed within a framework of international law and multilateral institutions and in pursuit of the common interest.

It is pretty difficult to understand how we could ever take down Saddam after emasculating our own power by refusing to pursue the common interest. In retrospect, I am also forced to admit that we completely failed to consider Saddam's interests either.

With a scope of all nations in the world, it is difficult to come up with a single true common interest shared by all. Is it any surprise that the UN is unable to come up with a approach to the genocide in Sudan (much less a solution)?

Power is only effective if your adversary believes that you are completely willing to use it.