Post-9/11 neoconservatism relied on a near-infinite supply of public will. To paraphrase Walter Russell Mead, neoconservatives may have grabbed the wheel of American foreign policy after 9/11, but they were able to drive it only so far because 9/11 had supercharged the engine. The engine was the American public’s willingness to expend blood and treasure across the globe. Today the engine is sputtering. Most Americans no longer believe that what we’re fighting for in Afghanistan is worth the cost of young American lives (even if the lack of a draft keeps them from taking to the streets to say so). And most Americans believe, rightly, that we can’t afford the war either. In retrospect, perhaps the most remarkable feature of post-9/11 neoconservative foreign policy was its virtual disregard for economics. None of the major neoconservative writers—Robert Kagan, Charles Krauthammer, William Kristol, Bernard Lewis—dealt much with international economic questions. And none of the key Bush administration hawks—Dick Cheney, Donald Rumsfeld, Paul Wolfowitz, John Bolton, Richard Perle—focused on economics either. Undergirding post-9/11 neoconservatism was the assumption that the money for a quasi-imperial foreign policy would always be there, and that, if necessary, domestic spending could always be slashed—and perhaps even taxes raised—to make sure the Pentagon was spared the ax. But that assumption no longer holds. Forced to choose between health-care spending and military spending, as they increasingly must do, most Democrats will choose the former. And forced to choose between military spending and tax hikes, Republicans in this Tea Party era will throw the Pentagon under the bus as well.