It's not far-fetched, therefore, to consider what economists call a counterfactual--what things would look like today if the U.S. had not invaded Iraq.

First, U.S. troops would still be in Saudi Arabia. Our troops were there because of the Saudis' fear of an Iraqi attack.

Imagine, also, trying to persuade Iran to abandon the development of nuclear weapons when Iraq--which had attacked Iran--was actively engaged in doing exactly that.

Before Saddam was deposed by the U.S. invasion, he was bidding for leadership of the Arab world in its opposition to Israel and U.S. policy in the Mideast.

In short, it would be difficult to construct a scenario in which the ultimate outcome of events in Iraq today would be as negative for the United States as a world in which Saddam remained in control of Iraq.