The Cost of the War in Iraq--Posner's Response to Comments
There were as usual a number of interesting comments. I respond to just a few.
First, on the numbers front, Steven Davis notes that I was wrong to say that the Davis, Murphy, and Topel updated study estimates the cost of the war at $323 billion; their updated estimate is $480-$630 billion. Leigh, Wolfers, and Zitzewitz remind me that they made a prewar estimate of $1.1 trillion.
Second, I was too cryptic in saying that 9/11 increased the risk to be anticipated from Saddam Hussein's possessing weapons of mass destruction. The thinking behind the statement was partly that 9/11 demonstrated a degree of danger to the United States from the Arab world that had not been fully understood, and partly that Saddam Hussein might feel "one-upped" by the demonstration of al Qaeda's ability to hit the United States hard, something Saddam had never succeeded in doing. He might have been spurred by the example to more aggressive action or even to cooperating with al Qaeda.
Third, I never suggested that the United States feared a direct attack by Saddam Hussein on the continental United States. The danger to the United States would be that Saddam Hussein's possession of atom bombs or other weapons of mass destruction would give him a freer hand in the Middle East, where of course the United States has significant economic and other interests. A re-invasion of Kuwait by Iraq would not have been out of the question had Saddam been allowed to obtain nuclear weapons and the missiles to deliver them long distances. There is the further question of what would happen to Iraq after Saddam Hussein died or became incapacitated or was assassinated or otherwise overthrown. If Iraq at that point had weapons of mass destruction, they might well fall into terrorist hands