Gender, War, and World Order sets out to explore questions about whether there are significant differences in the opinions of men and women on issues of national security. If so, what causes those differences? And how do they matter in political practice?

The first chapter of the book engages hypotheses about sex difference in national security opinions based on essentialism, economic change and political mobilization, socialization, threat perception, and a state’s geopolitical position. In the second chapter, Richard Eichenberg finds little evidence of underlying differences in worldviews between men and women, especially outside of the United States. He then proceeds to provide evidence that women are more likely to object to defense spending correlated with violence and the making of war than defense spending generally. In chapter 4, he uses the example of torture to make the argument that sex differences matter “at specific times under specific circumstances” (p. 4). Although Eichenberg finds, across 26 events in US history since 1980, a “gender gap” in support for the use of military force, that gap has varied significantly in magnitude across those events. Chapters 6 and 7 present a cross-national comparison, suggesting that national context affects whether there is a gap between men’s and women’s opinions and the size of any gap.

At the end of his presentation of evidence, Eichenberg argues that the presence of violence is the biggest predictor of whether there is a gender gap and that the size of the gender gap is affected by the level of economic development and women’s political economy in any society. He also concludes that sex differences are more pronounced in the United States than elsewhere. As the book concludes, Eichenberg argues that the nonlinear development and trajectory of differences in opinion on issues of national security mean that we should not expect a pacification of policy related to the progression of women’s political equality, because “there is no guarantee that a changing balance of public opinion will yield a trend toward less militant international policy” (p.151).

This book weighs in on a number of key theoretical questions across American politics and international relations concerning public opinion, gender, and security issues. Are women more likely to oppose the use of military force than men? Are men more likely to favor strong national security policies than women are? Are women more peaceful than men? Is there a gender gap in national security opinions? If so, what is the source? These questions often have crossover appeal to the policy world, where media outlets, nongovernmental organizations, and international organizations often look for connections between women and peace.

There is, however, significant debate in the field about how to address questions of gender and security that are implicated in the discussions in this book. Gender, War, and World Order is well written and very clear when Eichenberg specifies what is being investigated and how. He repeatedly operationalizes “gender” as a distinction between men and women. References to a “gender gap” or “gender divide” or “gender difference” across the book are references to how women and men may or may not think or act differently. As I read Gender, War, and World Order, I found it difficult to make those same logical jumps. I have trouble thinking of people in a dichotomy of male and female and ignoring nonbinary, transgender, intersex, and genderqueer people. In addition, biological sex does not necessarily map onto gender. A significant amount of feminist work talks about sex as male, female, and other categories and discusses gender as masculinities and femininities, concepts that are related but not necessarily in a direct or linear way. Although Eichenberg touches on this in his rejection of what he calls the “essentialist hypotheses” (which “emphasize biological sex” and “often derive from evolutionary biology” to suggest that “women are more likely to oppose war” [p. 11]), the book continues to discuss sex and gender as if the two map to one another or are interchangeable. Given that Eichenberg never actually discusses what he believes constitute the categories of “men” and “women,” this conceptual vagueness looms over the discussions of potential gender differences in opinions about national security.

Another vagueness can also be found across the book. The title references “world order,” and the book claims evidence from across the globe to discuss potential gender divides in opinions about national security. At several points, Eichenberg discusses differences between the United States and the rest of the world, groups countries regionally, or talks about national characteristics. In these discussions and across discussions of national security, it is not clear what the state means substantively; Eichenberg’s investigation of how “societal and institutional variables” interact with “a country’s strategic situation” (p. 151) takes the state to be natural and unproblematic. Although these concepts are taken for granted across a wide variety of research, they make Gender, War, and World Order much more limited than it could have been if it had a careful conceptual exploration and operationalization of gender, culture, and the state. Such an addition would have helped Eichenberg balance even more intricate discussions across the six groups of hypotheses addressed in the text.

Gender, War, and World Order does amass an impressive amount of survey data from a wide variety of security issues and events both in the United States and in a variety of places across the world. Early in the book, Eichenberg bemoans an “evidence gap” about the gender gap on national security (p. 6). This book goes a long way toward addressing that gap by providing survey and interview data about hypothetical and actual public events. The data presented in this book are likely to be useful to a wide variety of researchers interested in gender, security, and public opinion.

Eichenberg wields that large amount of evidence to suggest that the purported “gender gap” is much more complicated than many scholars and media outlets often assume. The book finds variation across events, types of national security, different states, and different times—enough to make the argument that there is not some progressive, linear relationship between women’s political participation and less violent foreign policies. In my view, this is a significant contribution for two reasons. First, it makes an argument that instrumentalizing women and their political participation in the service of claims about the potential for more peaceful policy outcomes is unlikely to be fruitful. Second, that claim can then be leveraged to make a broader argument about promoting gender equality for its own sake, rather than because of some essentialist claims about what women are or could be in politics.

Overall, Gender, War, and World Order is a welcome complication of assumptions about women’s peacefulness, full of welcome data about sex and public opinion. More complex analyses of both gender and national difference would make the book a stronger empirical and theoretical contribution, but as it is, it is useful, accessible, and a positive development in the literature.