Before ISIS took control of the Iraqi city of Mosul in 2014, the Al Khasfa sinkhole just south of the city was estimated to be around 400 metres deep. Today, it is far shallower – the result of at least 4,000 bodies thrown by the group into the chasm, sometimes by the busload, during its three-year reign of terror. For those whose loved ones were lost or remain missing, Al Khasfa could hold answers about their fates.
Iraqi government forensics teams, overseen by judicial officials, began carefully exhuming bodies from the sinkhole on Sunday. The task of documenting and perhaps, eventually, prosecuting ISIS crimes is a gargantuan one for Iraq. Even today, no one knows how many people were killed by ISIS, though it is certain that what lies in Al Khasfa is merely the tip of the iceberg. But the path to a reckoning has been made much harder by the fact that Iraqi authorities have chosen to go it alone.
Eleven months ago, an Iraq-based UN expert team for investigating crimes committed by ISIS ceased operations after its host state requested the UN Security Council end its mandate. When it was established in 2017, Unitad was considered a revolutionary project in international justice. But its final months were marred by a blame game between its staff and Baghdad. The latter frequently accused the team of withholding evidence of ISIS’s crimes from Iraqi authorities, while Unitad employees in turn argued that Iraq’s flawed justice system and use of the death penalty prevented such co-operation.
The truth, as is so often the case, lies somewhere in between. Critics say Unitad’s mandate, which included finding a way to contribute evidence to Iraqi prosecutions, was flawed from the outset. Iraq’s judicial bureaucracy and culture of summary judgement proved immune to meaningful reform. And Unitad’s own enthusiasm and transparency are said to have waned in its final year of operations. Its staff did not even attend a June 2024 hearing at the UN to renew its mandate, and civil society organisations have accused it of failing to leave behind a roadmap for how the evidence it collected could be used.
At the time of its closure, Unitad-compiled evidence had been used successfully in just 15 prosecutions, most of them in Europe. In the meantime, the hopes for justice of so many Iraqis, Syrians and others victimised by ISIS are stuck in limbo.
But Iraq’s push to close Unitad was likely about more than legal differences. The country is engaged in a wider effort to wind down UN oversight in its domestic affairs, which includes the termination of the UN Assistance Mission to Iraq by the end of 2025, in a bid to reassert its sovereignty.
ISIS’s atrocities, however, were never a purely domestic matter. The group’s members are guilty of a host of war crimes and crimes against humanity – offences international law has long held are too severe to be left exclusively to one country to prosecute. This was made clear enough in the conviction of an ISIS member in a Portuguese court last year for war crimes committed in Iraq. The court relied on the principle of universal jurisdiction, citing the international nature of the crimes. And while the prosecutors received help in their investigation from a judge in Mosul, it is difficult to see how such an outcome could be achieved with equal transparency and rigour in a politicised Iraqi courtroom today. Indeed, experts say evidence from thousands of ISIS-related trials in Iraq, in which defendants’ basic rights were allegedly routinely discarded, supports that view.
If Iraq’s goal is to prove that its sovereignty offers sufficient scope to attain justice for ISIS’s victims, then its institutions must rise to the occasion with meaningful reform in the way prosecutions are handled and convictions are meted out. Otherwise, the evidence is at risk of being thrown from one sinkhole into another.

