Last month marked the 100^th anniversary of the first major genocide of the 20^th century. The massacre of over one million Armenians by the Ottoman government in 1915 continues to fuel a fierce debate about what constitutes “genocide,” which groups were victims, and who were the criminals. It is past time, however, for the world to acknowledge this genocide, and many others that have never received the international recognition they are due.

Ever since Raphael Lemkin, a Polish-Jewish legal scholar, first used the term “genocide” to describe the Nazi extermination of Europe’s Jews, both victims and perpetrators of mass persecution have wielded it as a verbal weapon. While victims and their descendants demand acknowledgment and compensation, perpetrators and their descendants seek to avoid historical stigma and payment for crimes that were often government-ordered.

The problem in part lies in the term’s flexible definition. The Convention on the Prevention and Punishment of the Crime of Genocide, adopted by the UN General Assembly in December 1948, defines genocide as acts “committed with the intent to destroy, in whole or in part, a national, ethnical, racial, or religious group.” Such acts include “killing members of the group,” “causing serious bodily or mental harm,” and “inflicting conditions of life calculated to bring about physical destruction.” This definition provides little clarity as to how many people or what proportion of a population would need to be murdered to qualify as genocide, and it is quite easy to see how charges such as “inflicting…mental harm” might be open to dispute.

However unclear some of its particulars might be, however, the UN’s definition can be readily applied to numerous massacres during the 20^th century in which a substantial portion of an ethnic or religious group was massacred by a government within its own territory or in the territory of a neighboring state. In the case of the Armenians, what began as the arrest of political leaders and intellectuals by the Ottoman authorities in April 1915 culminated in the wholesale killing of the able-bodied male population and the deportation of women, children, the elderly, and the infirm on death marches, which involved deliberate starvation.

Turkey has denied that its predecessor committed genocide, while for the large Armenian diaspora the genocide is the core national mobilizer. In the U.S. the Armenian lobby has been pressing successive administrations to acknowledge the genocide explicitly as such. But the White House does not want to endanger its relations with Turkey, a key NATO ally. In addition, Armenia remains a Russian protectorate that occupies a fifth of the territory of Azerbaijan, a growing energy exporter that can undercut Moscow’s monopolization and manipulation of energy supplies to Europe. Even when the definition of genocide seems self-evidently to apply, politics intrudes on the attempt to have one recognized.

The Armenian genocide is not the only mass slaughter to have little recognition as such from the international community. The largest number of genocides in the 20^th century was committed in the Soviet Union and yet none of them has been acknowledged by Moscow or recognized by the United Nations.

In the most blatant example, the Stalinist regime deliberately starved to death between four and seven million Ukrainian peasants in the early 1930s after forcing them into collective farms and stealing all their food supplies. The goal was to break the backbone of Ukrainian resistance to communist rule. Soviet security forces also committed genocide against dozens of ethnic groups, either through mass deportation, large-scale massacres, or forced labor with starvation rations. This included Chechens, Crimean Tatars, Balkars, Poles, Lithuanians, Latvians, Estonians, and numerous smaller nations.

During World War II, numerous genocides were pursued in different parts of Europe, including by rival nationalists in German- and Soviet- occupied territories. For instance, in German-occupied Yugoslavia the mass murder of Serbs by Croatian fascists or of Muslims by Serbian nationalists would qualify as genocide according to the wording of the UN Convention.

Today, in the post-Yugoslav area, there is a danger that some mass murders may again be swept under the rug for the sake of political expediency. The mandate of the International Criminal Tribunal for the Former Yugoslavia (ICTY) is expiring, with all trials and appeals to be completed by the close of 2015. The Tribunal is to transfer its responsibilities to the International Residual Mechanism for Criminal Tribunals, established in July 2013. This body is supposed to complete all outstanding trials, including those of several indicted war criminal, but the results are uncertain.

The genocide definition has a mixed record in ex-Yugoslavia. Some legal experts assert that “ethnic cleansing” perpetrated primarily by the Bosnian Serb army in the early 1990s constituted genocide. This was confirmed by a resolution of the UN General Assembly and the U.S. Congress. However, other legal scholars convinced the ICTY and the International Court of Justice (ICJ) to declare only the Srebrenica massacre in July 1995 to be a genocide. In other words, the rapid murder of 8,000 people was considered a more severe crime than the accumulated extermination of over 100,000 civilians, mostly Bosnian Muslims.

It appears that the EU and the U.S. want to bury the war crimes question and finally close the chapter on Yugoslavia’s violent disintegration. Such intentions may have their merits, but unrecognized crimes, an absence of justice, and lack of reconciliation have a way of resurfacing with a vengeance and sparking new wars. After all, the cover-ups by Tito’s communists, in which state officials who ordered mass executions evaded justice, provided propaganda ammunition to nationalist forces during the 1990s.

Similarly, the lack of Moscow’s recognition and accountability for Soviet genocides remains an outrage for Russia’s neighbors, including in Ukraine, which is witnessing new war crimes instigated by the Kremlin.

It is time to acknowledge all the genocides that were committed during the 20^th century, whatever the identity of the ethnic, national, or religious groups. This is not only an issue of political far-sightedness but also a question of basic morality and our often-trumpeted “Western values.” Surely, this is the very least that all innocent victims should have expected when they were slaughtered simply because of their identity or convictions.