New York - Around the world, people's understanding of why rape happens usually takes one of two forms. Either it is like lightning, striking some unlucky woman who was in the wrong place at the wrong time (an isolated, mysterious event, caused by some individual man's sudden psychopathology), or it is "explained" by some seductive transgression by the victim (the wrong dress, a misplaced smile).

But the idea of a "rape culture" - a concept formulated by feminists in the 1970's as they developed the study of sexual violence - has hardly made a dent in mainstream consciousness. The notion that there are systems, institutions, and attitudes that are more likely to encourage rape and protect rapists is still marginal to most people, if they have encountered it at all.

That is a shame, because there have been numerous recent illustrations of the tragic implications of rape culture. Reports of widespread sexual violence in India, South Africa, and recently Brazil have finally triggered a long-overdue, more systemic examination of how those societies may be fostering rape, not as a distant possibility in women's lives, but as an ever-present, life-altering, daily source of terror.

The latest "rape culture" to be exposed - in recent documentaries, lawsuits, and legislative hearings - is embedded within the United States military. As The Guardian reported in 2011, women soldiers in Iraq faced a higher likelihood of being sexually assaulted by a colleague than they did of dying by enemy fire.

So pervasive is the sexual violence aimed at American women soldiers that a group of veterans sued the Pentagon, hoping to spur change. Twenty-five women and three men claimed that they had endured sexual assaults while serving, and lay the blame at the feet of former US Defense Secretaries Donald Rumsfeld and Robert Gates. The reason, the lawsuit claims, is that these men oversaw an institutional culture that punished those who reported the assaults, while refusing to punish the attackers.

When Maricella Guzman reported a sexual assault in her first month of service in the Navy, instead of being "taken seriously," she says, "I was forced to do sit-ups." Women soldiers who had served in Afghanistan came forward to speak with the filmmakers Amy Ziering and Kirby Dick, whose Oscar-nominated film The Invisible War exposed the scale of the problem. The fear of rape at US-held battlefields led directly to endemic illnesses caused by dehydration: women at the front, serving in 110-degree heat (43 degrees Celsius), did everything possible to avoid drinking, because rape was so common in the latrines.

The tales of colleagues, and even superiors, assaulting soldiers whose lives they are supposed to protect - stories that reveal the license that the attackers must have felt they had - are harrowing enough. What becomes clear from story after story in The Invisible War is a consistent - indeed, nearly identical - narrative of concealment, cover-up, and punishment of alleged victims, for whom justice was almost impossible to obtain through institutional channels.

One obvious cause of this is that, in the US military, soldiers report sexual assault to their superiors in the chain of command, rather than to a separate, independent investigative body. As testimony by servicewomen (and some men) reveals, this almost inevitably creates powerful incentives to quash investigations. After all, it looks bad for the supervisor if a rape took place on his (or her) watch. It also makes intimidating complainants easy, because they are direct subordinates.

Is this reporting structure unique to the US military, or is it the norm in mixed-gender armed forces in other advanced democracies (or near-democracies)? Unfortunately, rape is so poorly documented and researched that such data are not readily available.

But, apart from this corrupt reporting structure, there probably are other aspects of US military life that foster "rape culture." Researchers from Stanley Milgram to Phillip Zimbardo have shown that atrocities can be committed more easily when ordinary subjects (that is, not sociopaths) become desensitized in various ways. This can include exposure to authority figures who normalize violence by framing it as acceptable or good; depictions of the "other" as less than human; and widespread impunity.

Given that these conditions increase people's propensity to commit atrocities, or to torture, is it any surprise that rape is so prevalent in the US military? Countless iterations of torture as a tacit policy in US-run military prisons, from Abu Ghraib to Bagram, have normalized violence beyond the international laws of war.

Similarly, the nature of US military tactics - which in recent years have frequently conflated civilian "collateral damage" with combat against armed enemies - has dehumanized the victims. And the message from the top (as Rumsfeld put it, "the enemy" is not dressed in a uniform these days) fosters further desensitization.

Finally, the many unpunished crimes already committed in the US military - such as torture - have encouraged too many soldiers to assume that impunity prevails.

Can the US military's rape culture be changed? Congressional leaders have held hearings and vowed reform - but there have been hearings and vows before. Yet another lawsuit regarding sex crimes was dismissed this year.

There can be no meaningful change until US military leaders reestablish the rules and the code of honor that have protected soldiers - and the armed forces' legitimacy and prestige - for generations. Soldiers respect their service and themselves when they know that there is a high normative bar between licit battlefield aggression and extralegal mayhem.

Indeed, most of the US military men and women I have met long to embody the role of a warrior who acts on a bright-line understanding of the difference between right and wrong. Of course, moral clarity may inevitably yield to the fog of war. But that is arguably much more likely to happen when soldiers have become inured to lawlessness in their own ranks.