The U.N.: Still a Useful organization?

In a recent Washington Post editorial, there was a suggestion that maybe the UN was still a useful organization -- just look at Lebanon and Darfur -- everyone turned to the UN for peacekeeping. Well, let's just look at that. It's quite striking to me that the war in Lebanon even took place to begin with and then was allowed to last so long. And Darfur? Well, the killing still continues on a daily basis -- African Union peacekeeping forces or not. So should we rate this as a success? After all, what other alternatives do we have, right?
That's just the point. The UN has failed miserably at peacekeeping and peacemaking. Should we be surprised? How could we be given the configuration of the international system? The UN is not meant to succeed -- and given its current configuration -- it never will.
Now this is not to suggest that we should turn to world government -- but if we truly want to have a more effective organization to curb war and human rights abuses we need to give it more power -- and by the way -- it can't simply be the lackey of any particular country or countries....