The top surviving officials of Adolf Hitler's regime were indicted on crimes including the extermination of racial, national, and religious groups.
In a televised trial 15 years later in Israel, Adolf Eichmann -- the man responsible for the implementation of the Nazi plan to eliminate Europe's Jews -- faced inarguable evidence that he, too, had contributed to genocide on a massive scale.
"The accused, together with others, during the period 1939 to 1945, caused the killing of millions of Jews in his capacity as the person responsible for the execution of the Nazi plan for the physical extermination of the Jews known as the Final Solution of the Jewish problem," a news anchor reported at the time.
Eichmann was hanged on 31 May 1962.
The Nazi trials and the 1948 Genocide Convention reflected a determination in the world community to prevent a recurrence of the Jewish Holocaust. But it was not enough.
Mass murder of national, ethnic, and tribal groups has continued with depressing frequency -- most recently in Sudan, where pro-government Arab janjawid militias have been blamed for the deaths of tens of thousands of black Sudanese in the western region of Darfur.
The United States has said the killings in Darfur constitute genocide, providing a basis for action under international law. But there has virtually been no intervention to date.
Why has the international community failed to keep genocide from happening?
Bernard Hamilton is the president of the Leo Kuper Foundation, a nongovernmental organization working for the eradication of genocide. Speaking from London, he said the international community has been slow to follow on the promise of the Genocide Convention.
"I think because of the gravity of the crime [of genocide], there was a certain fear about either being accused of that, or accusing people of that act," Hamilton said. "So the international community was somewhat cautious in setting up implementation mechanisms for the Genocide Convention. It moved very early, but it moved very cautiously, in the sense that it didn't set up an International Criminal Court [ICC], it didn't set up a monitoring mechanism to alert the UN of the advent of genocide."
Hamilton said the recent establishment of the ICC is a major stride toward putting the convention to work. So, too, is the new UN office of special adviser on the prevention of genocide. Argentinian rights lawyer Juan Mendez was named to the post in 2004. His first major project -- a summation of the situation in Darfur -- was presented to Secretary-General Kofi Annan on 25 January.
But other hurdles remain.
Rene Lemarchand is a professor emeritus at the University of Florida and an expert on comparative genocide. He said a consistent part of the problem has been the Western notion that victims of mass murder are most often "far-away people about whom we know nothing."
"Another reason is our abysmal ignorance of the events leading to genocide and our inability or unwillingess to take appropriate steps to prevent the worst from happening," Lemarchand said. "Just consider some of the countries where the worst killings have happened since the Holocaust -- Bosnia, Cambodia, Rwanda, Burundi. I don't think there is one American out of a thousand who could have identified these countries on a map of the world before these countries were the site of mass murder, of genocide."
But while a public might learn of such a tragedy only as it is happening, politicians and other officials are often able to see a brewing catastrophe before it escalates.
As early as 1915, U.S. diplomats were urging Washington to intervene in the mass killing of an estimated 1 million Armenians by Turkey. Ankara has long denied charges of genocide.
Western officials also warned about the potential for genocide in Bosnia and Rwanda. But it was not enough to prevent the murder of more than 7,000 Muslim men and boys in Srebrenica in 1995, or the Hutu killings of up to 750,000 minority Tutsi in the Rwandan genocide the previous year.
Lemarchand said Western countries are often reluctant to dedicate military and logistical power to situations that do not directly threaten their national interests. They are also cautious about leveling accusations they themselves could face.
The United States ratified the Genocide Convention only in 1986, and after numerous amendments aimed at preventing the government from ever facing genocide charges itself. It has also declined to join the International Criminal Court.
Another problem is the term "genocide" itself. The convention's definition is used as a guideline for genocide cases in the UN's war crimes tribunals for Yugoslavia and Rwanda. But Lemarchand said the rules are vague and indistinct -- making it easy for countries to remain on the sidelines as bloody conflicts unfold.
For example, the convention defines genocide as an act to destroy a national, ethnic, or religious group "in whole or in part" and says genocidal crimes include "killing members of the group." Such a definition, Lemarchand said, leaves genocide open to interpretation.
"And this raises the question -- how many people should be killed before you call the killings a genocide? Is the killing of 20 people a genocide? Should it be 200? Should it be 2,000? I think, quite frankly, the problem with affixing the label of genocide to these terribly violent situations anywhere in the world is that a lot of time is lost on trying to agree on whether this is or this is not genocide. And as more and more people are being killed, nothing is being done," Lemarchand said.
This week's commemorations to mark the 60th anniversary of the liberation of the Nazi death camp at Auschwitz are once again -- however briefly -- focusing the world's attention on the persistence of genocide.
It remains to be seen whether the international community can summon the political will and public support to prevent future killings, like the 1970s slaughter of 1.7 million Cambodians under Pol Pot's Khmer Rouge, or Saddam Hussein's killing of some 5,000 Kurds in Halabjah in 1988.