The war in iraq cost per month

The nonpartisan Congressional Budget Office (CBO) has estimated the cost of "prosecuting" a war against Iraq at up to $9 billion per month, on top of an initial outlay of up to $13 billion for the deployment of troops to the Persian Gulf region.
In a letter to the House and Senate budget committees, CBO provided Congress with cost estimates for an armed conflict with Iraq, based on recent similar U.S. military operations including those in the Balkans, Afghanistan, and the 1990 Gulf War.