(Cornell University Press)

When I began conducting research in eastern Congo in 2005, it was nearly impossible to avoid conversations about rape during war. All of my interview subjects — civil society leaders, workers with nongovernmental organizations, U.N. officials — brought it up, even though it was not my topic or something I asked about. The area (which U.N. official Margot Wallstrom would call the “rape capital of the world” five years later) was racked by sexual violence, with clinics and hospitals full of women who had suffered injuries from particularly violent forms of gang rape, often involving sharp objects and weapons. And no matter where I went, I was introduced to survivors. There seemed to be no rhyme or reason to who was targeted; the youngest gang-rape survivor I met was 5, and the oldest were elderly women. Survivors were of all ethnicities and had been attacked in both urban and rural environments.

The crisis would shortly thereafter begin to grab headlines, with everyone from Nick Kristof and Eve Ensler to Hillary Clinton and Oprah Winfrey trying to “help,” some more effectively than others. There was no doubt that the crisis merited that level of attention. It was bad, and given how few resources were available to those victimized by armed actors before the wave of international attention, there is no doubt that the donations that those stories and efforts generated helped.

But what no one could definitively explain was why this horrific violence was happening. And without that explanation, activists, doctors and supporters could only hope to heal the physical, psychological and spiritual wounds of rape. Stopping it before it started was far more complex.

While a number of scholars had done innovative research on the topic, there was still no explanation as to why some of Congo’s armed groups engaged in sexual violence while others did not, and we did not understand why extreme forms of gang rape were so often used to terrorize women as opposed to other forms of the violent crime. Some posited that it was because the fragility of the Congolese state and a decade of civil war had led to a breakdown of societal norms and taboos against such behavior, making wartime rape in the Congo essentially an opportunistic activity. Others argued that it was related to conceptions of masculinity and the long history of powerful people exploiting vulnerable Congolese populations. Others thought it might be done as part of an explicit military strategy. We just didn’t have a comprehensive answer.

Dara Kay Cohen’s brilliant, groundbreaking book, “Rape During Civil War,” helps provide those much-needed answers about motivations. Cohen uses a sophisticated mixed-methodology approach to argue that rape is a way that armed groups socialize combatants in hopes of making fighters who are often randomly thrown together a cohesive, effective group that is able to provide for its members during war. Participating in gang rape, an activity done as a group, helps bring these fighters together by building “bonds of loyalty and esteem from initial circumstances of fear and mistrust.”

Cohen calls this phenomenon “combatant socialization.” Using an original, cross-national data set of accounts of rape in civil wars around the world over a 32-year period, she shows that the need to build cohesion among fighters is as good an explanation or better for why some armed groups rape and others do not, compared with alternative claims such as the idea that rape is a function of ethnic hatred or societal inequality between genders. Cohen builds on these findings with three qualitative case studies based on hundreds of interviews with combatants, survivors, community leaders, and those who work in the human rights field and/or directly with survivors in Sierra Leone, El Salvador and East Timor.

Importantly, Cohen also finds that opportunism and material resources play a role in motivating armed actors to rape alongside the combatant socialization explanation, which helps explain why sexual violence in combat so often seems randomly directed, as in the Congo case.

Cohen’s findings help explain why some armed groups rape and others do not: Not every armed group needs to build social cohesion, because the members already know and trust one another, whether from previous relationships or shared ethnic or geographic identities. The fighters in those groups joined because they believed in the cause or because someone they knew persuaded them to come along. But in many armed groups (and, often, in national armies), many people don’t volunteer for service; they are forced into it. Whether through press-ganging (in which national armies force individuals to fight) or forced recruitment (such as when child soldiers are kidnapped and forced to fight with groups like Sierra Leone’s Revolutionary United Front or Uganda’s Lord’s Resistance Army), combatants are fighting for a cause they may not understand or support alongside people they neither know nor trust. Gang rape, Cohen shows, is a way to build a common identity, to make fighters feel stronger in their masculinity and to tie fighters together in a way that ultimately builds a stronger fighting force.

Although beautifully written, Cohen’s book is not an easy one to read, and those who may be triggered by accounts of sexual and gender-based violence should take care. But as a researcher who has long wondered about the causes of horrors I first witnessed as a graduate student, I found myself a bit in awe of Cohen. Her ability to address this difficult subject in a way that is analytical and sensitive, and to point to clear policy prescriptions that could apply her findings to very practical solutions to the problem of wartime rape is admirable. Cohen’s approach to generating new data through innovative and careful methodologies is one that future scholars who want to study rape and other sensitive topics should follow. “Rape During Civil War” is an agenda-setting book, a model of high-quality scholarship and a must-read for anyone interested in stopping rape in conflict before it happens.