Amal Clooney is a barrister at Doughty Street Chambers specializing in international law and human rights. Zainab Ahmad is a partner at Gibson, Dunn & Crutcher and a former prosecutor with the Justice Department. Clooney and Ahmad are counsel to Yazidi victims of ISIS, along with the Center for Justice and Accountability.

In June 2015, U.S. Army Special Forces raided the Syrian compound of senior Islamic State leader Abu Sayyaf. Abu Sayyaf earned grim notoriety in the United States as the brutal captor of American aid worker Kayla Mueller, who, after suffering appalling abuse at his hands, died in February 2015 under uncertain circumstances.

During the raid, Abu Sayyaf was killed, and U.S. forces took his wife Nisreen Bahar, known as Umm Sayyaf, into custody. Together, the Sayyafs took part in an ISIS campaign of murder and sexual violence against the Yazidis that the United Nations and the United States have characterized as genocide. The couple enslaved at least 11 Yazidi girls and women at their home.

We represent five of those women. They have recounted that they were kept bound in locked rooms, starved, told that they were subhuman devil-worshippers, and made available for rape by ISIS militants. But as we will be reporting later this week at a U.N. conference on crimes against Yazidis, we are still trying to bring Umm Sayyaf, one of their torturers, to justice. If we succeed, we will do so despite the government of the United States, which has shown a surprising reluctance to charge international suspects with crimes against humanity.

Umm Sayyaf’s crimes violated American law and U.S. prosecutors could have pursued the trial in a U.S. court. Indeed, the Justice Department filed charges against her. But they chose not to follow through with prosecution and instead turned her over to Iraqi authorities.

Since that time, our clients have never been informed about any arrest for rape, genocide, torture and enslavement. They have never been invited to testify at any trial. Umm Sayyaf’s current whereabouts are unknown.

Although officials assure us that they pursue those who harm Americans to all corners of the globe, they frequently turn the perpetrators over to other governments for prosecution, often without regard to the capabilities of those governments. The outcome of that strategy, in this case, is that an ISIS member who allegedly facilitated the enslavement and rape of an American woman was only charged with one terrorism-related offense and has never faced trial in an American courtroom for that charge.

This problem goes beyond our case. The United States’ reluctance to prosecute war crimes is systemic. It has refused to legislate against crimes against humanity as a discrete offense — one that is criminalized in more than 50 countries. The U.S. war crimes statute is narrow in scope. And although torture and genocide are federal crimes, the United States has historically been reluctant to levy such charges.

This reluctance contrasts sharply with European states such as Germany that are using “universal jurisdiction” to charge Syrian officials and ISIS commanders with crimes of torture, war crimes and genocide committed abroad, even when the crimes are committed by and against noncitizens.

American reluctance to prosecute at home is compounded by an unwillingness to support war crimes prosecutions abroad. The International Criminal Court counts two-thirds of the world’s countries as members, but the United States stands with Russia and China in declining to participate. Although President Bill Clinton signed the treaty establishing the ICC, President George W. Bush unsigned it, and it was never ratified. President Donald Trump’s former national security adviser John Bolton pronounced the ICC “dead to us,” and Trump’s administration went as far as imposing financial and travel sanctions against its prosecutor and staff.

It has not always been this way. The United States played an indispensable role in the creation of the International Military Tribunal in Nuremberg that prosecuted German officials after the Second World War. And in the 1990s, the United States used its position at the United Nations to sponsor the prosecution of war crimes in The Hague.

The Biden administration has signaled an intention to revive this legacy. It set a new tone by revoking the Trump administration’s “inappropriate” sanctions on the ICC, and stated that U.S. opposition to investigations that could ensnare American or Israeli troops is best handled through “engagement.” Secretary of State Antony Blinken announced that renewed support for international justice by the United States will “realize the promise of justice for victims of atrocities.”

They deserve nothing less. So the United States should seek the extradition of Umm Sayyaf to face American justice for her alleged crimes. Prosecutors should expand the charges and seek her transfer to the United States to stand trial.

Her conviction will not heal the devastating injuries she caused to her victims, but holding Umm Sayyaf accountable through a fair and open process is a step toward justice. And the broader Yazidi community deserves the support of the United States to bring other ISIS terrorists to justice in an international court. It is time for the United States to revive a proud legacy and honor the promise of justice for genocide.

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