The three cases in this level took place after the Genocide Convention existed, which makes them painful tests of the world's promise to prevent and punish genocide.

Cambodia (1975 to 1979)

The Khmer Rouge, a communist movement led by Pol Pot, seized Cambodia's capital, Phnom Penh, in April 1975 and ruled from 1975 to 1979. It emptied the cities and forced the population into rural labor collectives, abolished money, markets, schools and religious practice, and sought to rebuild society from scratch. Former officials and soldiers, educated people, monks, and ethnic minorities such as the Vietnamese and the Cham Muslims were targeted, and the party also purged its own members. Through execution, starvation, overwork and untreated disease, about 1.5 to 2 million people died, roughly a fifth to a quarter of the population. The regime fell in January 1979, after Vietnam's army invaded.

Cambodia raises a definitional question. Much of the killing targeted people for class or political reasons, which the Genocide Convention does not cover. Many scholars call the whole episode genocide in a broad sense, while a UN-backed tribunal in Cambodia in 2018 convicted two surviving senior leaders of genocide against the Vietnamese minority (one of them also against the Cham) and of crimes against humanity more widely.

Rwanda (1994)

Rwanda's population was mostly Hutu, with a Tutsi minority and a small Twa community. Belgian colonial rulers had issued identity cards recording ethnicity, hardening the categories, and waves of anti-Tutsi violence after 1959 drove many Tutsi into exile. In 1990 the Rwandan Patriotic Front, a rebel army formed largely by Tutsi exiles, invaded, and civil war followed. A 1993 peace agreement was fiercely opposed by Hutu extremists, whose radio station spread dehumanizing propaganda.

On 6 April 1994, the plane carrying Rwanda's president was shot down; who fired on it is still disputed. Within hours extremists began killing Tutsi and moderate Hutu, using prepared lists, roadblocks, the army, militias and many ordinary civilians. Over about 100 days, roughly 500,000 to 800,000 Tutsi were killed by most scholarly estimates, with the Rwandan government and some researchers giving higher figures, along with many Hutu who opposed the killing. A UN peacekeeping force was already in the country, but after ten Belgian peacekeepers were killed, the Security Council reduced the force to a few hundred. The genocide ended when the Rwandan Patriotic Front took control of the country in July 1994.

Srebrenica (1995)

During the war in Bosnia and Herzegovina (1992 to 1995), which followed the breakup of Yugoslavia, Bosnian Serb forces carried out campaigns of ethnic cleansing against Bosniaks (Bosnian Muslims) and Croats. In 1993 the town of Srebrenica, crowded with Bosniak refugees, was declared a UN “safe area”; by 1995 it was guarded by lightly armed Dutch peacekeepers. In July 1995 Bosnian Serb forces overran it, separated men and boys from women, and over several days killed about 8,000 Bosniak men and boys, later moving the remains between mass graves to hide them. The international tribunal for the former Yugoslavia and the International Court of Justice both ruled that this was genocide, and the Bosnian Serb wartime leaders Radovan Karadžić and Ratko Mladić were convicted.

Other cases

These five cases are not the only ones. Others that courts, commissions or many scholars have described as genocide include the destruction of the Herero and Nama peoples in German South West Africa (1904 to 1908), mass killings in what became Bangladesh in 1971, violence against Maya communities in Guatemala in the early 1980s, Darfur in the 2000s, and attacks on the Yazidis in Iraq in 2014.

Worked example: what outsiders knew

A recurring question in all three cases is what the outside world knew, and when.

Cambodia. The Khmer Rouge sealed the country off, and few foreign journalists were present. Refugees who reached Thailand told of forced labor, starvation and executions, but some outside observers doubted their accounts, partly because the stories seemed too extreme and partly for political reasons. The full scale became clear only after 1979.

Rwanda. In January 1994 the commander of the UN force, the Canadian general Roméo Dallaire, cabled UN headquarters with an informant's report that extremists were registering Tutsi and hiding weapons. He asked permission to seize the arms caches and was told not to. After the killing began, governments avoided the word genocide for weeks, in part because using it might have created pressure to act under the Convention.

Srebrenica. The enclave's vulnerability was well known. The UN had declared it a safe area without providing the forces needed to defend it, and requests for air support as Bosnian Serb forces advanced came to little. A 1999 UN report acknowledged serious errors of judgment, and in 2002 the government of the Netherlands resigned after an official report on the Dutch role.

The common thread is not total ignorance. In each case, some warnings existed. What was missing was a willingness to believe them and to accept the costs of acting. That gap, between knowing and acting, returns in the final level of this course.