Hitchens:

More to the point, one has to be prepared to support a campaign—or a cause—that is going badly. The president has been widely lampooned by many a glib columnist for saying that increased violence is not necessarily a cause for despair and may even be evidence of traction. He is, in fact, quite right to take this view, which was first expressed, to my knowledge, by Gen. John Abizaid. Those who murder the officials of the United Nations and the Red Cross, set fire to oil pipelines and blow up water mains, and shoot down respected clerics outside places of worship are indeed making our point for us. There is no justifiable way that a country as populous and important as Iraq can be left at the mercy of such people. And—here is my crux—there never was.

I couldn't say it better.