William Howell, Saul Jackman, and Jon Rogowski give us an important study of the domestic politics of war in the United States. Their thesis is that war increases the leverage that the executive has in bargaining over policy with the legislature, thereby shifting national policy toward the president’s preferences. The mechanism is the increased prioritization of national over local outcomes by members of Congress during wartime.

After a brief review of existing arguments on presidential power, the authors lay out the theoretical core of The Wartime President, the “Policy Priority Model.” This is a formal model of the resources and preferences of the executive and the legislative branches, positing that the default focus of the president is on national outcomes, and each congressperson on local outcomes. In peacetime, this can lead to divergence in policy preferences between the two branches of government and a stymied executive. In wartime, by contrast, members of Congress are more likely to think in terms of the good of the nation, to take account of patriotic surges in public opinion, and to defer to the expertise advantage that the president has in understanding what is best for the nation as a whole. The executive is more likely to get their way.

The authors conceptualize the influence of war as a continuous rather than a dichotomous variable: some wars will work more to the president’s advantage than others. Howell, Jackman, and Rogowski develop a set of criteria for ascertaining the nationalizing influence of five modern wars, arguing that World War II and the Afghanistan/Iraq wars (treated by the authors as a single conflict) had the most nationalizing effect, whereas Korea, Vietnam, and the first Persian Gulf War had less.

Through careful empirical analysis (reflecting what must have been herculean labors), the authors find their predictions to be mostly borne out. They examine spending and voting patterns in the Congress across the five wars. In World War II and Afghanistan, Congress was significantly more likely to grant the president’s requests in the budget and to vote in a way consistent with the president’s ideology. Once the wars ended, Congress reasserted its independence. In Korea, Vietnam, and the first Persian Gulf War, the picture is much less clear, findings which are consistent with the authors’ hypotheses.

Subsequent chapters explore these dynamics through case study analysis, including an admirably frank discussion of cases where the predictions of the model are at odds with the evidence, such as George W. Bush’s failed efforts to reform social security despite the model’s suggestion that he should have had great leverage over Congress due to the nationalizing effect of the post-9/11 wars.

I find the book to have considerable strengths. It offers a genuinely novel way to think about the wartime presidency. The authors offer a plausible argument and convincing data on the manner and extent to which presidents benefit domestically, and not just on foreign policy, from war.

The book is also praiseworthy in the diversity of its methods. Formal modeling and data analysis are combined with qualitative investigations, and so the book is at the leading edge of the move toward multimethod triangulation in political science, as well as fitting in with the modern information-resources-bargaining paradigm that dominates the study of American political institutions.

I see some problems with the argument, though. The initial review of the literature on presidential power struck me as a little thin, confined to the mid-twentieth-century works of Edward Corwin, Clinton Rossiter, and Arthur Schlessinger, Jr. (the authors suggest that little work of consequence has been done since then). Richard Neustadt’s treatise on presidential power goes unmentioned, which seems an unfortunate omission given Neustadt’s stress on the resources that presidents have in a situation whereby separated institutions share powers.

With regard to the policy priority model itself, scholars of different orientations will react to it very differently. To those favorably disposed toward formal theory, the model is a welcome advance and will, I suspect, become the centerpiece of an important research program. The authors ably state the view of formal theorists that far too often in political science, assertions are made without proper elaboration of the logic underlying them. Thus, most studies of the presidency are viewed by the authors as atheoretical, by which they mean not based upon formal models.

The retort of nonformal theorists is that these models necessitate unrealistic simplifying assumptions and result in predictions that we could have reached through the application of common sense. This camp, I suspect, will question some of the underpinnings of the model: All presidents are assumed to be more expert on national policy than all members of Congress; and presidential ideology is rendered as a simple matter of Democrats being liberal and Republicans being conservative.

Although the central causal mechanism of the book—the shift from a local to a national focus by members of Congress—is plausible, it is mostly discussed in the aggregate and observed indirectly, rather than demonstrated in specific cases of legislators’ thinking. I would have welcomed an in-depth account of the reasoning of a member of the legislative branch concerning the way the model posits as a verification of the microfoundations of the argument.

Finally, I found it questionable to code Afghanistan and Iraq as a single case. This seems counterintuitive given the very different dynamics and levels of public and congressional support for both of these wars, and the roller-coastering fortunes of the United States—and the presidents—over the course of these long conflicts.

Caveats aside, though, Howell, Jackman, and Rogowski have produced a major work of theory and empirical analysis. The implications of their model extend, as they acknowledge, far beyond the wartime presidency and offer a general theory of presidential power in relation to Congress. An analysis of the Obama presidency using this framework, undertaken by the authors or by others working from their framework, would be fascinating and important. The book is likely to become an important reference point for those working on interbranch bargaining in the U.S. political system.