In an age of fierce partisanship, divided government, and political gridlock alongside increasingly robust international institutions, how is it that US Presidents from both parties continue to act unilaterally and unchecked in the use of force? This question is especially pressing given popular distrust of standing armies and state power in American political culture and war's declining legitimacy as an instrument of state power worldwide.

Most commentators who have addressed this problem have focussed on Presidents and their will to power, along with the means by which they amassed and exerted power. Often such work paints Congress as the victim of presidential encroachments on its Constitutional prerogatives. In The American Warfare State, political scientist Rebecca Thorpe challenges this view, presenting Congress as complicit in the rise of a permanent “warfare state” that has fatally undermined its own authority in the conduct of US foreign policy. Specifically, she argues that “[e]conomic dependence on a war economy” has left legislators predisposed to provide Presidents with the weapons of war and unwilling to prevent their use, even when Presidents wield those weapons without Congressional consent (159).

Historically and legally, Thorpe argues, the only real Constitutional check on presidential war-making has been Congress's power of the purse. Throughout the first 150 years or so of US history, if Presidents wished to wage war they had to ask Congress to pay for it. And war's high costs in blood and treasure made Congress reluctant to do so, since legislators risked public ire when they passed those costs on to voters in the form of taxes, tariffs, and conscription.

Such calculations changed during World War II and the Cold War. Instead of imposing costs on Americans, those conflicts sparked thirty years of prosperity as unprecedented military spending stimulated economic growth via “military Keynesianism,” particularly in the least developed precincts of rural America. Military contracts went disproportionately to the sparsely settled and capital-starved South and Southwest, not “inadvertently,” as Thorpe suggests, but by design, as southern Democrats who dominated Congress at mid-century used defense spending to lift their constituents out of poverty. Unlike established industrial cities, the newly prosperous exurban “Sunbelt” relied on defense dollars for economic growth, leaving its political class loath to see the threat of war disappear. Indeed, many scholars have argued that the Sunbelt was and is more accurately a “gunbelt.”

Thorpe turns such work to questions of presidential war-making, arguing that “defense dependence” rendered Congress's power of the purse a dead letter. Through quantitative analysis of roll call votes and committee assignments from the 1990s, she shows that legislators' positions on weapons and war, at least in the Clinton era, hinged on their “economic reliance” on military contracts. Since virtually every corner of the US receives substantial sums of such spending, she further maintains that reliance upon it was most acute in areas with few other industries, essentially equating population scarcity with defense dependency to explain why rural legislators endorsed military spending with greater zeal than their urban counterparts. Economic reliance, she argues, is especially key in winning support for military programs among rural Democrats, if only because Republican support for war is nearly universal whereas Democrats show greater variation.

Thorpe's analysis is insightful and important, if burdened by social-scientific jargon that most humanists will find impenetrable. Among other things, she helps to explain why Democrats largely failed to restrict presidential war-making and costly weapons even after the party's most vocal constituents turned against both during and after the Vietnam War – rural Democrats still relied on military spending. And she is certainly correct that Presidents could not wage war with so few constraints were it not for the fact that Congress supplied them with the arsenal to do so. Thorpe focusses our attention on the fundamental political economy of American empire without being distracted by clamorous partisanship that masquerades for substantive differences.

Yet Thorpe's work prompts as many questions as it answers. To what degree can data from the mid-1990s explain patterns that have persisted since the 1940s when so much has changed in US politics over the last seventy-five years? And why do rural politicians prefer building weapons to other means of delivering dollars to their districts? Why have they retrenched on NASA, for instance, which once funneled federal dollars southward? And given that rural districts and states skew conservative and vote Republican while cities skew Democratic, does Thorpe mainly reaffirm what we already know, namely that Republicans have, since Vietnam, become so enamored of war that they struggle to break free of its allure even during Democratic presidencies? After all, her analysis shows that even the most defense-dependent rural Democrats support the warfare state with no more enthusiasm than the least defense-dependent Republicans. Finally, Thorpe says too little about the costs of the warfare state. If Congressional reluctance to pay for war was once its main impediment, then more attention to the advent and evolution of financing war and its weapons with borrowed money deserves further study.