From the Congressional Research Service (via Federation of American Scientists):
"With enactment of the FY2008 Consolidated Appropriations Act (H.R. 2764/P.L. 110-161) on December 26, 2007, Congress has approved a total of about $700 billion for military operations, base security, reconstruction, foreign aid, embassy costs, and veterans’ health care for the three operations initiated since the 9/11 attacks: Operation Enduring Freedom (OEF) Afghanistan and other counter terror operations; Operation Noble Eagle (ONE), providing enhanced security at military bases; and Operation Iraqi Freedom (OIF).
This $700 billion total covers all war-related appropriations from FY2001 through part of FY2008 in supplementals, regular appropriations, and continuing resolutions. Of that total, CRS estimates that Iraq will receive about $524 billion (75%), OEF about $141 billion (20%), and enhanced base security about $28 billion (4%), with about $5 billion that CRS cannot allocate (1%). About 94% of the funds are for DOD, 6% for foreign aid programs and embassy opera! tions, and less than 1% for medical care for veterans. As of April 2008, DOD’s monthly obligations for contracts and pay averaged about $12.1 billion, including $9.8 billion for Iraq, and $2.3 billion for Afghanistan."
http://lawprofessors.typepad.com/law_librarian_blog/2008/08/the-cost-of-ira.html