The following article was written to mark International Justice Day (17 July 2021) and is based on ongoing research I am conducting into the linkages between mass atrocities and transnational organized crime (see here for some preliminary insights). A version of the piece was originally published at Al Jazeera.

Mass atrocities don’t come cheap.

A common misconception is that everything must fail in order for international crimes – war crimes, crimes against humanity, and genocide – to be perpetrated against civilian populations. On the contrary, many things need to align for governments, terrorists, or rebel groups to commit atrocities. They need persuasive politics, organised institutions prepared to follow orders, and buy-in from key constituencies. And they need money – lots of it.

After another year in which the demand for accountability for international crimes far outweighed the supply of justice, this July 17 – International Justice Day – is a useful time to highlight the importance of tackling the funding of atrocity perpetrators. One way to do so is to connect the prosecution of mass atrocities with the lucrative, transnational crimes that fuel them.

It is hard, if not impossible, to think of a conflict since the end of World War II where mass atrocities were perpetrated but in which transnational organised crimes played no role. The commission of transnational crimes, such as human and drug trafficking, money laundering, the illicit trade of oil, ivory and antiquities, and so on, has contributed mightily to filling the coffers of war criminals, terrorists, and genocidaires.

Consider some examples. The notorious Lord’s Resistance Army (LRA), a rebel group which operates in swaths of Central Africa, has committed a litany of war crimes and crimes against humanity since its war with the government of Uganda erupted in the mid-1980s. In recent years, the LRA has been able to survive and continue its abduction of children to fight in its ranks because of its illegal trafficking of ivory through Sudan.

In Syria and Iraq, the Islamic State of Iraq and the Levant (ISIL) has been accused of every international crime on the books, including the attempted genocide of the Yazidi population. ISIL’s economy depended on transnational organised crimes, including the illicit sale of oil through Turkey and on to international markets. While its destruction of culturally protected sites received significant media attention, ISIL also preserved some antiquities in order to sell them, illegally, on black markets. Such transnational crimes permitted ISIL to survive – and terrorise civilians – for as long as it did.

On rare occasions, the link between illicit and lucrative crimes and mass atrocities has received attention from courts. In 2012, former Liberian President Charles Taylor was convicted and sentenced to 50 years in jail for aiding and abetting war crimes and crimes against humanity in Sierra Leone. Central to his conviction was Taylor’s involvement in the trade of “conflict diamonds” in order to fund the rebel groups that terrorised Sierra Leonean civilians.

More recently, the Kosovo Specialist Chambers and Specialist Prosecutor’s Office was established, with many hoping it will shed new light on whether the Kosovo Liberation Army engaged in human organ trafficking following its war and alleged counter-ethnic cleansing campaign against Serbia in the late 1990s and early 2000s.

All of these examples illustrate that the very same perpetrators who commit mass atrocities are also and simultaneously involved in the commission of money-making transnational organised crimes. Given how complex and difficult it is to effectuate meaningful accountability for mass atrocities, as well as the glacial pace of international criminal justice, it is high time to consider placing a greater emphasis on investigating perpetrators of international crimes for their involvement in illicit trade networks.

More can and should be done to destabilise the funding of perpetrators of mass atrocities. This would require a concerted effort on the part of state institutions as well as international organisations, like the International Criminal Court (ICC), to link the investigation of transnational organised crimes and international crimes. There is some progress on this front, with countries like Uganda establishing special divisions capable of investigating both crime sets. Others have promised to do the same. The former ICC Prosecutor Fatou Bensouda raised the spectre of investigating human trafficking in Libya as a possible crime against humanity, although there is no evidence of concrete action on the matter to date.

One promising route would be to ensure that investigators examining mass atrocities are better equipped to collect evidence of transnational organised crimes. Where they are unable to use that evidence to build their own cases, they should share it with states and institutions who are able to do so and who can thus disrupt illicit networks. States should likewise explore the possibility of setting up a permanent international tribunal with the specific mandate of tackling transnational organised crimes, perhaps in conjunction with efforts to create an international anti-corruption court.

Every year, transnational organised crime generates hundreds of billions of dollars. But it is not just costly in dollars and cents. It costs human lives. Tackling such illicit crime could thus help protect civilians from violence and atrocity. It has done so before.

Few gangsters were as notorious in the early 20th century as Al Capone. Widely believed to have been responsible for numerous murders and violent crimes, Capone was ultimately convicted for tax evasion. Incarcerating “Scarface” for a crime he could more easily be prosecuted for meant that he was off the streets and no longer a direct danger to society. In other words, putting Capone behind bars for tax evasion deterred his ability to commit violent crimes in the future.

That is likewise the promise of linking the investigation and prosecution of mass atrocities with transnational organised crimes. Disrupting illicit trade networks and prosecuting perpetrators of transnational crimes would neuter the ability of genocidal regimes, terrorist organisations and rebel groups to fund their violence, thereby deterring atrocities.

Follow the money and perhaps the perpetrators of atrocities around the world will meet their match.