This might sound like chicanery by George W Bush and his cronies - or characteristic incompetence - but Bilmes and Professor Joseph Stiglitz, the Nobel laureate economist from Columbia University, have established not only that the number wounded in Iraq and Afghanistan is far higher than the Pentagon has been saying, but that looking after them alone could cost present and future US taxpayers a sum they estimate to be $536bn, but which could get considerably bigger still. Just one soldier out of the 1.4 million troops so far deployed who has returned with a debilitating brain injury, for example, may need round-the-clock care for five, six, or even seven decades. In present-day money, according to one study, care for that soldier alone will cost a minimum of $4.3m.

Estimating long-term costs using even the second, moderate scenario, Bilmes tells me: "I think we are now approaching a figure of $2.5 trillion." This, she says, "includes three kinds of costs. It includes the cash costs of running the combat operations, the long-term costs of replenishing military equipment and taking care of the veterans, and [increased costs] at the Pentagon. And then it includes the economic cost, which is the differential between reservists' pay in their civilian jobs and what they're paid in the military - and the macroecono mic costs, such as the percentage of the oil-price increase."