Editor's note: This report includes descriptions of sexual and physical violence.
Accounts of alleged sexual violence coming out of Ukraine in recent weeks have been grim. A woman raped repeatedly by a Russian soldier after her husband was killed outside Kyiv. A mother of four gang raped by Russian soldiers in Kherson. The body of a Ukrainian woman found dead — naked and branded with a swastika. A woman raped by a Russian commander on the day tanks entered the village of Kalyta.
The number of reports that have emerged since the start of the war in late February suggests that rape in Ukraine at the hands of Russian soldiers may be widespread. Those fears were further crystallized earlier this month following the Russian withdrawal from Bucha, a suburb of the capital Kyiv, where some two dozen women and girls were "systematically raped" by Russian forces, according to Ukraine's ombudswoman for human rights, Lyudmyla Denisova.
"What we've seen in Bucha is not the random act of a rogue unit," said U.S. Secretary of State Antony Blinken. "It's a deliberate campaign to kill, to torture, to rape, to commit atrocities. The reports are more than credible. The evidence is there for the world to see."
History has shown that rape in wartime has been used to horrifying effect. Such crimescan be used to humiliate, intimidate and punish. Victims are primarily women and girls, though men and boys can also suffer sexual violence. Rape has been used as a tactic of genocide — to shape the future of a country through forced impregnation. Gang rape has even been a grotesque way for disparate troops to bond. Rape in war zones can be opportunistic or systematic — and it nearly always goes unpunished.
What's happening in Ukraine
Two months into the war, much remains to be investigated and confirmed about the prevalence of sexual assaults in Ukraine. NPR has been unable to independently verify individual accounts. But in an interview with Morning Edition, Matilda Bogner, the head of a United Nations team documenting possible human rights abuses in Ukraine, says she has received "dozens" of allegations.
"It is difficult to fully confirm sexual violence because it's often the type of case where victims don't want to speak publicly, and they're often not in safe areas where it feels safe for them to speak out, or where they have received the services that they need," she said.
Organizations such as the United Nations, Human Rights Watch and La Strada Ukraine have begun to document sexual violence in Ukraine. So, too, have Ukrainian officials.
"The cases we documented amount to unspeakable, deliberate cruelty and violence against Ukrainian civilians," said Hugh Williamson, Europe and Central Asia director at Human Rights Watch, in a report earlier this month. "Rape, murder, and other violent acts against people in the Russian forces' custody should be investigated as war crimes."
Russia has denied allegations of rape and other atrocities by its soldiers in Ukraine. "It is a lie," Kremlin spokesman Dmitri Peskov said in response to one Ukrainian woman's account of Russian soldiers shooting her husband dead then raping her repeatedly.
But Dara Kay Cohen, a professor of public policy at the Harvard Kennedy School and author of the book Rape During Civil War, says she's watching what's happening in Ukraine with "a great deal of trepidation, worry and horror." From the accounts that are public, she has noticed some disturbing trends.
"One of them is reports of gang rape, which is actually very common in wartime," she tells NPR. "In fact, gang rape in particular is by far the most widely reported form of rape during periods of conflict. And that's in stark contrast to peacetime, where gang rape is relatively rare, even in places where we know rape to be quite common."
Another disturbing trend she has noticed is a lack of any attempt to hide such crimes. In some conflicts, she says, perpetrators will attempt to bury the evidence, perhaps by killing the victims or witnesses. While information remains limited, Cohen says this brazenness by Russian soldiers suggests to her that commanders are, at a minimum, "aware of what's happening."
"It doesn't suggest ... individual soldiers going off to engage in opportunistic sexual violence. It suggests something that is at the very least being tolerated by the command, if not ordered," she says.
One example she points to is the violence that took place in Bucha. Denisova, the Ukrainian ombudswoman for human rights, described the situation to the BBC: "About 25 girls and women aged 14 to 24 were systematically raped during the occupation in the basement of one house in Bucha. Nine of them are pregnant. Russian soldiers told them they would rape them to the point where they wouldn't want sexual contact with any man, to prevent them from having Ukrainian children."
Cohen says this account reminds her of some of the horrors that took place in Bosnia during the Balkan Wars of the 1990s, when women were raped and impregnated.
The atrocities in Bucha are "genocide wrapped in gender-based sexual violence," wrote Sharon Block, a professor of history at the University of California, Irvine. "The soldiers could have killed the women and girls to prevent reproduction. But they chose to inflict sexual harm as a sign of their power."
Russian officials have claimed that the country's military operation in Ukraine is being distorted and that the atrocities in Ukraine have been "staged" by Ukrainian forces to be circulated by Western media.
Rape is not common in all conflicts
Mia Bloom, a professor at Georgia State University and an international security fellow at the think tank New America, says it's important to understand that although rape is a war crime, it is not something that is present in all wars.
And danger can come from different directions. In one case noted by The Guardian, a Ukrainian teacher had been dragged into the school library by a Ukrainian soldier who tried to rape her. She reported him to the police and the man was arrested.
"It's not just a normal part of war. Not all soldiers rape," Bloom tells NPR. Bloom and Cohen are both a part of the Sexual Violence in Armed Conflict project, which collects data on the subject.
She says because there is variation between conflicts — some have rampant sexual violence, while others have little — there isn't a consistent theory of when and why rape is used in war.
But scholars have identified different strategic aims. One goal can be to weaken or alter a society by forcibly impregnating women with children fathered by the enemy. She points to the Serbian "rape camps" in Bosnia, where women and girls say they were raped until they were pregnant — and then imprisoned to prevent them from getting abortions.
"That's not accidental," says Bloom. "You're allocating resources. And the way they were thinking is they would undermine the cohesion of the community because that next generation would be giving birth to babies that were half and half — that had the ethnicity of their father, despite the fact that there was no communication with the father."
Rape can also weaken social ties if the victim is then rejected by her own family or community, as has been the plight of many Nigerian girls and women kidnapped and impregnated by Boko Haram fighters. Even when the women escape and make it home, community members have told researchers the children had "bad blood" transmitted from their fathers.
But Bloom believes that an underlying feminism in Ukrainian society could serve to reduce the stigma that has often been the burden of survivors of sexual violence.
"Women have played such an important role in the resistance and in fighting the Russians that the likelihood of the women being ostracized and blamed is very low," Bloom says.
Militaries have used rape as a war weapon
In Ukraine, experts say there are indications that Russian soldiers are using rape in a number of ways — as a form of punishment, as well as with perhaps systematic, genocidal aims.
While the precise motivation remains unknown, Cohen says the reports coming out of Ukraine suggest something other than opportunistic violence.
"These are incredibly violent rapes where there are photos circulating of women's bodies that have been branded, women who have been raped multiple times, women who have been held as sexual slaves, women who have been raped until they're pregnant," Cohen says. "All of these things are beyond just an opportunism argument and are indications of rape being used as some kind of weapon."
It's a view that was shared this month by the British ambassador to Ukraine, Melinda Simmons.
"Rape is a weapon of war," Simmons said. "Though we don't yet know the full extent of its use in Ukraine, it's already clear it was part of Russia's arsenal. Women raped in front of their kids, girls in front of their families, as a deliberate act of subjugation."
Justice for survivors is rare
As the fighting continues, investigations into possible war crimes in Ukraine, including rape, have already begun.
In the first two weeks of April, the Ukrainian ombudsman received 400 reports of rape committed by Russian soldiers, the Kyiv Independent reported. And a U.N. mission has received 75 allegations of rape against Ukrainians.
But the track record of holding anyone accountable for rape during wartime isn't long.
The International Criminal Tribunal for Rwanda convicted the mayor of Taba, Rwanda, in 2001. Ratko Mladic, the former Bosnian Serb military commander, was found guilty by the International Criminal Court in 2017 of genocide and war crimes, including the mass rape of women and girls. Slobodan Milosevic, the former Yugoslav leader, faced similar charges but died in jail in 2006 before the end of his trial.
Russia is not a party to the ICC, nor is the United States. Ukraine isn't either, but it has recognized the court's authority, so the court could prosecute atrocity crimes committed in Ukraine.
The ICC's top prosecutor has said he will fast-track an investigation into war crimes in Ukraine. But Ukraine's foreign minister has said he has little confidence in organizations like the ICC to prosecute crimes like rape.
"When Russian soldiers rape women in Ukrainian cities — it's difficult, of course, to speak about the efficiency of international law," the minister, Dmytro Kuleba, said at a forum last month.
Cohen says that holding people to account for rape in wartime is rare. At the highest levels, it's usually difficult to prove that the rape was ordered by someone in command.
"It is very rare to ever have smoking gun evidence that rape was ordered from the top down," she says.
And for the rank-and-file soldiers accused of committing such atrocities, prosecutions can be exceedingly hard to come by.
"There is some degree of accountability, but it is rare," says Cohen. "But I think that that does not imply, however, that we shouldn't be doing our best to collect all of the documentation that we possibly can in order to potentially hold perpetrators accountable."
Speaking with The Atlantic earlier this month, Ukrainian President Volodymyr Zelenskyy said real victory will come only when the perpetrators are tried, convicted and sentenced. But justice likely won't come quickly, he conceded.
"How long do we have to wait? It's a long process, these courts, tribunals, international courts," he said.