The last Congress delivered a big win for atrocity accountability by passing the Justice for Victims of War Crimes Act, which President Joe Biden signed into law in January of this year. The law closed several critical loopholes in U.S. law on atrocity crimes, adding jurisdiction over war crimes committed abroad when the perpetrator is present in the United States, regardless of the nationality of the perpetrator or victim, and eliminating the statute of limitations for most war crimes (a significant practical barrier to enforcement). These changes brought U.S. law far closer to its obligations under international law, including the Geneva Conventions. While there has not previously been a U.S. prosecution using the war crimes statute, the numerous examples of individuals accused of war crimes ending up in the United States suggest that with due attention and resources, these changes can bolster the United States’ ability to deliver some measure of justice to more victims of atrocities.

But even with progress on war crimes, current U.S. law still severely limits the role U.S. courts can play in holding perpetrators of atrocity crimes accountable because of a significant gap in the legal framework for crimes against humanity (which often occur outside of any war context). Crimes against humanity involve a specific set of grave human rights violations committed as part of a widespread or systematic attack against a civilian population (more on that below). If the United States is serious about fighting impunity for the repeated patterns of atrocities committed in Ukraine and many other situations around the world, it should close the crimes against humanity loophole in U.S. law as soon as possible.

Momentum for Atrocity Accountability

The political will to finally reform U.S. law on war crimes stemmed in large part from bipartisan efforts in both Congress and the executive branch to ensure working paths exist to pursue accountability for atrocities committed in Ukraine. In a September Senate Judiciary Committee hearing, DOJ and DHS officials testified that addressing gaps in U.S. law would expand the tools available to U.S. authorities, and expand access to justice for victims of atrocities, without which the United States would effectively be a “safe haven” for certain types of human rights violators. The hearing raised several other shortcomings of U.S. law on atrocities (including clarifying the extraterritorial applicability of the Alien Tort Statute, the subject of another proposed bill last session that did not advance). Though the hearing again demonstrated bipartisan interest in expanding U.S. jurisdiction over war crimes and crimes against humanity, only the war crimes fixes were achieved during that session, leaving the void for crimes against humanity intact and U.S. agencies and courts without adequate options to provide justice for victims of those crimes.

Several experts, civil society coalitions, professional associations, and human rights advocates have repeatedly raised the problem (including a Working Group on Crimes Against Humanity within the American Bar Association chaired by Ambassador Scheffer). An initial bill was introduced by Senator Dick Durbin and colleagues in 2010 (past hearings here, here, here). Since then, cases pursued in some of the many national jurisdictions that already have crimes against humanity laws have provided compelling evidence of their utility: there have been multiple prosecutions of ISIS members in Germany for crimes committed against the Yezidis, cases filed by victims’ advocates in Argentina for crimes committed against the Rohingya and Uyghurs, and criminal cases against Syrian regime officials, all for crimes against humanity. In fact, crimes against humanity was the most common charge (66) found in Trial International’s 2022 report on universal jurisdiction cases, compared to 34 war crimes and 25 genocide charges.

Despite their frequency and despite consistent U.S. policy supporting atrocity accountability and prosecutions abroad, the U.S. government does not have its own legal authority to criminally prosecute perpetrators of crimes against humanity, even when alleged perpetrators are in the United States. This leaves a unique category of atrocities vulnerable to impunity.

The Crimes Against Humanity Gap in U.S. Law

A patchwork of U.S. law currently gives federal authorities the tools to prosecute perpetrators of war crimes (bolstered by the legislative updates described above), genocide, and the specific crimes of recruitment/use of child soldiers and torture, which now all include jurisdiction when the offender is present in the United States (among other jurisdictional bases, coverage of which remains inconsistent among the statutes). Of those statutory tools, only the torture statute has so far been used to pursue criminal accountability in the United States (Ross Roggio, Michael Sang Correa, Charles “Chuckie” Taylor,  Jr., the only conviction so far, and Sulejman Mujagic, who was charged but extradited). Additional existing federal laws punish isolated crimes (such as individual acts of murder) in limited circumstances, but these laws often do not cover crimes committed abroad, even when perpetrators are found in the United States.

Because of these limitations, prosecutors often resort to using immigration violations such as fraud and false statements (the utility of which is also limited by statutes of limitation) to prosecute and/or remove suspected international criminals from the United States. In many of these cases, involvement in crimes against humanity form the basis of the fraud allegations and evidence outlined in court. As one example, Liberian warlord Mohammed Jabbateh was convicted of immigration fraud and perjury in 2018 rather than for the most serious crimes that victim testimony demonstrated he and his fighters committed against civilians (murder, enslavement and sexual enslavement, torture, conscription of child soldiers, persecution, and other inhumane acts—all amounting to crimes against humanity) during Liberia’s first civil war.

These efforts can physically remove perpetrators from U.S. soil, but they often do not result in appropriate penalties fitting the scale and criminality of atrocities. Prosecuting the conduct that constitutes atrocities as “common” crimes or through immigration violations, as a sort of workaround, does not adequately recognize and respond to the unique social harm and extent of victimization inflicted on communities through widespread, systematic atrocities, and may not elicit the perpetrator’s full culpability. And although some alleged perpetrators have been prosecuted for crimes against humanity or other crimes in their home countries after being deported, others have not and thus may escape justice altogether. Lastly, as Ambassador Scheffer has previously noted, the lack of crimes against humanity provisions in the U.S. legal framework also means that if Americans are allegedly involved in crimes against humanity, either as perpetrators or as victims, the United States’ inability to investigate and prosecute those atrocities at the appropriate level of gravity could mean that there will either be no accountability for those crimes, or that prosecutions will be pursued in other legal venues, such as in the national courts of other countries or international tribunals with jurisdiction, rather than U.S. courts.

Crimes Against Humanity Laws Respond to Atrocity Situations that War Crimes Laws and Genocide Do Not

As defined in Article 7 of the Rome Statute of the International Criminal Court (ICC), crimes against humanity include certain acts (such as killing, extermination, torture, sexual violence, and persecution) when committed as part of a widespread or systematic attack against the civilian population. Crimes against humanity can include attacks against civilians during war (and therefore may overlap in part with war crimes), but they also cover a distinct set of crimes that occur in “peacetime,” leaving many cases unaddressed by war crimes laws (see USCIRF’s Legislation Factsheet). Crimes against humanity also uniquely recognize the use of a State or organizational policy to attack civilians, which Ambassador Beth Van Schaack noted in written testimony makes crimes against humanity laws “critical” for promoting accountability for senior leaders, who “are often instrumental in the design and execution of the state or organizational policy through which mass atrocities are committed.” And crimes against humanity include many atrocities that do not fit the limited technical legal definition of genocide. Research by Professor Leila Sadat has found that many modern atrocities are solely prosecuted as crimes against humanity — 30% of ICC cases have included only crimes against humanity charges. Because elements of crimes against humanity also often manifest as indicators and precursor acts for other atrocities, occurring before the onset of armed conflicts or more developed plans to destroy entire populations (what Sadat has called an “atrocity cascade”), crimes against humanity laws are also important tools for atrocity prevention.

War Crimes
War crimes, in contrast, are limited to serious violations of international humanitarian law occurring in the context of an armed conflict (drawn from various international legal sources including the Hague Conventions, Geneva Conventions and their Additional Protocols). Even with recent legislative changes, the provisions of the U.S. Code on war crimes do not include all war crimes under international law, and some were also decriminalized through the Military Commissions Act of 2006.

Rome Statute Article 8 contains an extensive illustrative list of war crimes, but it also demonstrates key challenges in their prosecution, which first requires a determination that violence has risen to the level of an “armed conflict,” and then whether the armed conflict is “international” or “non-international” in order to determine which exact rules apply as well as a potential nexus of the relevant conduct to the conflict. What’s more, as Ambassador Stephen Rapp previously noted, courts may deem crimes committed far from the “battlefield” not to be “war crimes,” even when they occur during an armed conflict. Those same challenges do not arise for crimes against humanity.

Crimes against humanity charges can also cover unique conduct of comparable gravity to war crimes. The crime of forced marriage, for example, which often occurs within the context of armed conflicts, but is not well captured by enumerated war crimes, has been successfully prosecuted in international courts as a crime against humanity (most recently in the Ongwen case at the ICC). Additional examples include post-election violence (e.g., ICC investigations in Kenya and Cote D’Ivoire); violence against peaceful protestors (e.g., 2009 stadium massacre in Guinea); and mass killings, enforced disappearance, torture, and deportation outside of armed conflicts (e.g., extra-judicial killings as part of the Philippines so-called “war on drugs,” or torture committed against perceived political opponents in Venezuela, or post-coup crimes in Myanmar).

Genocide
The challenges in prosecuting atrocities as genocide have been clearly articulated by experts (ex. here, here, here, here, here), and research on past U.S. atrocity determinations. Those challenges include the difficulty obtaining sufficient evidence of the highly specific “intent to destroy” a population as well as the limited protected groups covered by the Genocide Convention. Whether an atrocity qualifies as a genocide is often the subject of much public debate, government deliberation, and even judicial deliberation, with questions over classification sometimes clouding the atrocity response.

Importantly, it is very likely that acts falling short of the threshold or specific circumstances recognized as genocide within international law would constitute crimes against humanity. The crime of persecution, for example, has existed in international criminal law since the Nuremberg trials, and as part of the law of subsequent international tribunals including the ICC. Like the crime of genocide, the crime against humanity of persecution focuses on acts committed against particular groups based on perceived identity, with discriminatory intent (a lower threshold than the “specific intent to destroy” required for genocide), yet covers more recognized grounds (political, racial, national, ethnic, cultural, religious, gender or other grounds that are “universally recognized as impermissible under international law”) than the crime of genocide. Numerous past cases have exemplified the utility of crimes against humanity at capturing atrocities that were difficult to include within the limited definition of genocide, such as atrocities by the Khmer Rouge in Cambodia against particular political or social groups (not protected groups under the Genocide Convention); and the ICTR Media Case, where charges of persecution as a crimes against humanity allowed prosecutors to include broadcasts by Hutu extremists that helped direct the killing of Hutus politically-aligned with Tutsis. Present day examples include mass violence against political, social, or other groups not covered by the Genocide Convention or where evidence of genocidal intent is difficult to obtain (e.g., extensive crimes against the Uyghurs, which a UN’s report suggested “may constitute international crimes, in particular crimes against humanity”) and gender-based persecution (e.g., escalating attacks on rights of women and girls in Afghanistan), among others.

Impact on Accountability for Crimes Against Humanity in Ukraine and Beyond

The crimes against humanity loophole in U.S. law leaves the United States unprepared to deal with the slate of potential atrocities occurring in Ukraine and other situations, leaving the United States a safe harbor for perpetrators who come into U.S. jurisdiction. As exemplified above, there are many atrocity crimes not covered by war crimes or genocide statutes, for which having a crimes against humanity statute would be necessary to secure criminal accountability. One does not need to look hard for examples of these crimes occurring in ongoing atrocity situations today.

In Ukraine, for example, the OSCE mission of experts’ reports have already concluded that some patterns of violence committed in Ukraine (“targeted killing, rape, abductions, or massive deportations of civilians”) qualified as widespread or systematic attacks against a civilian population likely to constitute crimes against humanity. In 2020, before the invasion, the previous ICC Prosecutor had already found a reasonable basis to believe that war crimes and crimes against humanity had been committed in Ukraine as part of earlier situations, including alleged crimes such as persecution on political grounds and enforced disappearances occurring “in the context of the period leading up to and during the (ongoing) occupation of Crimea.” With the war ongoing, we cannot say for sure that all international crimes committed related to the conflict will be best captured by criminal laws on war crimes alone. Is the systematic targeting of certain groups of Ukrainian civilians, for example, better captured by crimes against humanity charges? Would attacks and violence against activists or dissidents critical of the war or against other persecuted groups within Russia, for which different officials might be highly responsible, rise to the level of crimes against humanity?  Could the “filtration system” and systematic deportation of Ukrainians to Russia, or crimes committed against Ukrainians after their deportation ,best be captured by crimes against humanity? Department of Justice Director of Human Rights Enforcement Strategy and Policy and Counselor for War Crimes Accountability Eli Rosenbaum raised this last concern during the September 2022 hearing (see recording at 1:27:50), noting the possibility that potential ambiguities in other areas of international law make this “another instance in which it would be very helpful to have crimes against humanity on American law books at long last.”

Critically, we do not know which perpetrators or victims of atrocities may end up in the United States and fall under U.S. jurisdiction, when perpetrators already in the country will be recognized by law enforcement or even victim communities, or for which specific crimes U.S. law enforcement authorities will be able to obtain sufficient evidence. Having statutes on genocide and war crimes but not crimes against humanity unnecessarily ties the hands of U.S. investigators and prosecutors when opportunities arise. Closing loopholes in the legal framework is therefore one way that the United States can stand up for justice in Ukraine and beyond.

Conclusion

There is no hierarchy of atrocity crimes. Genocide, war crimes, and crimes against humanity all describe and capture different forms of criminal conduct the international community has deemed unacceptable under any circumstances.  Crimes against humanity focuses on heinous crimes systematically targeting civilians on a massive scale, through abuses of power by States or other organizations. Just as the crime of genocide is an important repudiation of attempts to destroy communities, crimes against humanity also has important expressive value: it elicits truth about the scale of planning and preparation, recognizes unique harm and the targeting of protected groups, and includes acts that fall outside the technical bounds of genocide or war crimes, yet are atrocities nonetheless.

Closing the loophole on crimes against humanity in U.S. law would combat the perception that the same universal international legal obligations do not apply to all countries equally, or that victims of some crimes are more deserving of justice than others. And when human rights activists and experts in Ukraine are advocating for Ukraine to shore up their own domestic law on atrocities, correcting a critical flaw in U.S. law only strengthens U.S. credibility and ability to lead. Such a legislative reform would make good on expressed commitments to pursue justice, as updating the war crimes statute did, and help ensure that perpetrators of any atrocities cannot find a safe haven in the United States. It would also give U.S. government lawyers the tools they need to effectuate investigations and deliver justice for victims, including when the U.S. government  has special if not unique access to witnesses, evidence, or the perpetrators themselves.

The United States was instrumental in drafting definitions of crimes against humanity as part of the post-WWII Nuremberg and Tokyo tribunals, and as part of its leadership in negotiating the statutes of international ad hoc tribunals and the ICC Statute. During recent diplomatic discussions on a potential crimes against humanity treaty in 2021 and 2022, the United States delegation said the absence of a treaty addressing crimes against humanity was a “critical gap in the international legal framework” that the United States “strongly believe[d] should be addressed.” It is past time to live up to that commitment and fill the crimes against humanity gap in the United States’ own law.

Disclaimer: The views expressed herein represent the opinions of the authors. They have not been reviewed or approved by the House of Delegates or the Board of Governors of the American Bar Association and, accordingly, should not be construed as representing the position of the Association or any of its entities.

IMAGE: Eli Rosenbaum, director of the Human Rights Enforcement Strategy and Policy and counselor for War Crimes Accountability at the US Department of Justice, testifies about the war in Ukraine during a Senate Judiciary Committee hearing on “From Nuremberg to Ukraine: Accountability for War Crimes and Crimes Against Humanity,” on Capitol Hill in Washington, DC, September 28, 2022. (Photo by SAUL LOEB/AFP via Getty Images)