Although American military and Iraqi civilian casualties have declined in recent months, the rate of spending has shot up. A fully funded 2008 war budget will be 155 percent higher than 2004's, the CBO reports.
The reasons are numerous: the "surge" of additional US units into Iraq; rising fuel costs; fattened bonuses to attract re-enlistments; and particularly the need to "reset," that is, repair or replace worn-out, destroyed or damaged military equipment. Almost $17 billion is appropriated this year for advanced armored vehicles to protect troops against roadside bombs.
Looking ahead, both the CBO and Stiglitz-Bilmes construct two scenarios, one in which US troop levels in Iraq and Afghanistan drop sharply and early -- to 30,000 by late 2009 for the CBO, and to 55,000 by 2012 for Stiglitz-Bilmes -- and a second in which the drawdown is more gradual.
Significantly, the two studies view different time frames, the CBO calculating possible costs met in the next 10 years, while Stiglitz and Bilmes also include costs incurred during that period but paid for later, such as equipment replaced in post-2017 budgets.
This factor figures most in the category of veterans' medical care and disability payments, where the CBO foresees $9 billion to $13 billion in costs by 2017. Stiglitz and Bilmes, meanwhile, project $422 billion to $717 billion in costs over the lifetime of soldiers who by 2017 are wounded or otherwise mentally or physically disabled by the wars.
"The CBO is only looking 10 years out on everything," Bilmes noted in an interview.
For its part, a CBO critique suggested that Bilmes and Stiglitz might be overstating the expense of treating veterans' brain injuries, a costly category.
The two economists say their calculations are conservative, because they don't encompass many "hidden" items in the US budget. Their basic projections also exclude the potentially huge debt-service cost -- on which CBO approximately agrees -- and the cost to the US economy of global oil prices that have quadrupled since 2003, an increase analysts blame partly on the Iraq upheaval.
Estimating all economic and social costs might push the US war bill up toward $5 trillion by 2017, they say.
Their book already figures in the stay-or-leave debate over Iraq.
When Stiglitz testified on Feb. 28 before the congressional Joint Economic Committee, the ranking Republican, New Jersey's Rep. Jim Saxton, complained that such projections are too imprecise to help determine relative costs and benefits of the Iraq war.
Saxton said a rapid US pullout could lead to full-scale civil war and Iranian domination of Iraq, "enormous costs" that he said should be weighed in any calculation.