Iraq > Kyoto?

Magnificent catch by Cass Sunstein in the Washington Post: best guesstimates suggest that the total cost to the US of the conflict in Iraq is now $300bn and counting, which is basically the same amount of money as U.S. compliance with the Kyoto Protocol would have cost. In the latter case, of course, it's a large enough sum of money to cause "serious harm to the U.S. economy" (President Bush).

Doubtless one can drive either figure in either direction, so the comparison will never be uncontroversial. And as Sunstein points out, the return is at least as difficult to assess as the expenditure (is the world safer following the removal of Saddam?). But still -- are we reaching the point where even a fairly modest war is unaffordable? Or are we reaching a point where significant changes in the interests of reducing climate change are demonstrably cost-effective?