In the Washington Post today, Cass Sunstein says that complying with the Kyoto Protocol would have cost the U.S. a mere $300 billion—far less than the price we’re paying to watch an entirely useless bout of mass slaughter and chaos in Iraq. Indeed, there are a lot of things we could’ve done for a fraction of the price of war. We could’ve made sure that some of those 4 million infants dying each year—for want of knit caps and clean scalpels—don’t actually die. Or done more to halt the genocide in Darfur. That’s why the cost of war has to factor in all those useful things we could have done with those hundreds of billions of dollars but didn’t.