To regain international support and to have the resources of our allies available for a comprehensive strategy toward the region, the United States will have to produce a highly positive outcome in Iraq or withdraw. Since we are reasonably sure that a positive outcome is impossible, and certainly decades away in the best event, withdrawal is the most sensible course today.

Our military investment in Iraq is what economists call a "sunk cost." We cannot retrieve it by investing more there, no matter how much. Thus, to say that we cannot afford to fail is a costly illusion. We ensured failure when we decided to invade. Our choices now are to get out of Iraq early, regroup with our allies, and try to stabilize the region, or to continue down the present path in Iraq and risk the dissolution of the American-led international order.