The end of the Khmer Rouge, the gang of zealots who killed at least 1 million people in the four years they ruled Cambodia, was only a matter of time. Mercifully, it seems that time has finally come. Late last month, two of the three surviving leaders of the movement, Mr. Khieu Samphan and Mr. Nuon Chea, defected to the government of Cambodia. Although one Khmer Rouge leader remains in the field -- Mr. Ta Mok, the military commander known as "the Butcher"_ for the first time in three decades, Cambodia faces no real threat of internal insurgency. The government in Phnom Penh can now focus on nation-building, free from the distraction of a civil war.

Focus it should, but that does not mean that this grim chapter in Cambodian history is over. While the government of Cambodia devotes its efforts to restoring democracy, human rights and the rule of law, and promoting economic development, the rest of the world must demand an accounting from the survivors of the Khmer Rouge leadership. Mr. Nuon Chea was brother No. 2 in the party, second only to Pol Pot, who died last April; Mr. Khieu Samphan was head of state for the four years the party was in power. These two men deserve an international trial on charges of genocide.

Yet incredibly, upon defecting they were given red-carpet treatment: bouquets of flowers and a luxury hotel. Mr. Hun Sen, the prime minister of Cambodia who no doubt engineered the defections -- as he has for other former Khmer Rouge leaders -- then said that he was prepared to offer the men amnesty in the name of national reconciliation. That reversed an earlier pledge to hand over Khmer Rouge leaders to an international tribunal.