This projection, spelled out in a new 36-page report, is based in part on a little-noticed White House Office of Management and Budget estimate in July that projects $110 billion in fiscal year 2007 war funding, $8 billion less than the Defense Department required in fiscal year 2006.

“Based on this OMB projection, cumulative war funding . . . would reach about $549 billion,” states the Sept. 22 CRS report, “The Cost of Iraq, Afghanistan and Other Global War on Terror Operations since 9/11,” written by Amy Belasco, a defense budget expert.

The report also estimates that the monthly costs of operations in Iraq and Afghanistan will move 20 percent higher to $9.5 billion in 2006. In FY-05, the Pentagon spent $6.4 billion each month, on average, for Iraqi operations; $1.3 billion for operations in Afghanistan; and $180 million for enhanced base operations; in FY-06, those figures are on track to increase to about $8 billion for Iraq and $1.5 billion for Afghanistan, according to the report.

Between fiscal years 2001 and 2006, Congress has appropriated roughly $437 billion to fund a range of activities related to countering Islamic extremists around the world, including military operations, base security, reconstruction, foreign aid, embassy costs and veterans' health care, according to the report.

The Senate and House are slated to vote soon on a FY-07 defense appropriations conference bill that includes a $70 billion “bridge fund” to pay for war costs in the first part of the new fiscal year, which begins Oct. 1.

If enacted, this would fund the first few months of operational costs and bring total war appropriations to $507 billion. The July OMB projections estimated a total of $110 billion in FY-07 war costs, including the $70 billion bridge fund; this would leave the military in need of another emergency supplemental appropriations bill next spring for $40 billion to pay for continuing operations in Iraq and Afghanistan .