In a $600 billion enterprise, one has to be sympathetic to the Pentagon’s difficulties in trying to keep track of individual transactions. In many cases the D.O.D. is unable to specify what it has purchased from contractors. Asked about a $321 million payment made to Altria-Kraft, a Defense Department spokesperson took two weeks to explain that it was for “assorted groceries.” (Altria-Kraft also was unable to be more specific.) The D.O.D. had no data on the number of bullets used since 2003. And an Army spokesman eventually referred requests for information on purchases made from contractors such as Mars, Tyson Foods, and Dell to a public information officer at the contractor Halliburton, saying it is the best source for that information, “They have their feet on the ground over there.”

Heavy-construction and logistics companies like Halliburton benefit from the challenge of maintaining anything as large as the wars in Iraq and Afghanistan. These conflicts require a giant overhead investment in facilities and transport. A large fraction of the war funds go toward maintaining the gigantic supply chain that stretches from North America to Kuwait and Jordan and then overland and by air into Baghdad and points west, south, and north. Camp Anaconda (recently renamed Logistic Support Area Anaconda), northwest of Baghdad, is the central storage and distribution point for the Iraq war and one of the largest forward bases in the world. It sprawls over 15 square miles and has its own bus service and fleet of trucks supplying troops with everything from ice to medical equipment.

Keeping track of how much the U.S. is spending on the war has been complicated by the fact that, until this year, the Defense Department and the Bush administration have kept their spending requests separate from the general budget, instead moving them through Congress as supplemental appropriations. Each request becomes a vote on supporting the troops instead of what it actually is—maintenance of the increasing cash bleed. This strategy, coming at a time of persistent low inflation and a rising stock market, has created a distorted reality for most Americans in which, aside from the daily casualties, the war appears to be cost-free.

In fact, it is something of a mystery how little effect our current conflicts appear to have had on global markets or on domestic inflation or growth. That $600 billion could be spent over four years without any obvious effect is hard to fathom. By contrast, the outlay for World War II necessitated sacrifices such as rationing of food and fuel by virtually every American. One difference is that this war is being paid for with debt, whereas W.W. II was more of a pay-as-you-go proposition. This raises the question of whether there is a break point in the future. Does the war spending have some predictable impact on the supply of money available for borrowing? Might lenders like China, Japan, and Saudi Arabia reduce their purchases of U.S. Treasuries at some point, forcing the U.S. to raise interest rates drastically in order to make them more attractive? Or might these lenders seek an alternative to dollars, which would cause a steep drop in the greenback’s value? Both of these events might ripple through the economy in the form of inflation and a growth-choking liquidity crisis. All anyone can say for certain is that U.S. spending for the war puts us at least a trillion dollars closer to whatever that break point might be.

So until something changes, the battlefields in Afghanistan and Iraq represent a bizarre big-box-retail showcase for vast sectors of the global economy. Like some dreamy indulgent bachelor’s closet full of shiny electric guitars, the objects of war photographed for this portfolio are expensive, tangible, and exotic evidence of what $2 billion a week will buy. The U.S. will have inventories of these items long after the conflict is over. Our bases and communication infrastructure in Iraq and Afghanistan will endure as costly functional investments or ghostly ruins, whether our troops are there or not. While much of the world may oppose U.S. policy in Iraq, a big part of the globe also has a stake in minimizing that policy’s impact on the U.S. economy. At these levels of spending, the notion of a military victory or defeat is somewhat beside the point. Somewhere beyond $2 trillion, it is the global economy that may need the protection of a green zone as much as the city of Baghdad.

Before the invasion of Iraq in 2003, then Secretary of State Colin Powell famously warned President Bush that if you break it, you buy it. Powell was only partly correct. At last count, we’ve bought the equivalent of 10 Iraqs and will apparently buy at least a few more before we’re done.