Sarah E. Kreps, an associate professor of government at Cornell University, argues in Vox that America’s penchant for forgotten, seemingly never-ending conflicts stems from the way it finances them. “Contemporary wars are all put on the nation’s credit card, and that eliminates a critical accountability link between the populace and the conduct of war,” she writes. This is the thesis of her terrific new book, Taxing Wars: The American Way of War Finance and the Decline of Democracy. Kreps argues that wars no longer have a political cost to elected leaders because they don’t come with a financial cost to taxpayers. Therefore, the war in Afghanistan can rage for years on end because it doesn’t have a meaningful impact on the average person’s life—there’s no sense of shared sacrifice.