The trials could start late next year, assuming a few rich nations such as Japan and Australia donate enough money to run them, and Cambodia's current leaders don't put up more obstacles. Under a formula worked out with the United Nations last year, a majority of the judges will be Cambodians, with a minority being foreign jurists selected by the UN. That was necessary in order for Prime Minister Hun Sen, himself a former low-level Khmer Rouge, to support the trials. In power for two decades, Hun Sen wants to keep control of a process that might open up his own past to scrutiny and that of many of those around him, as well as China's role with the Khmer Rouge.

Even if flawed, however, the trials would help Cambodians come to terms with a regime that caused the deaths of as much as one-fifth of the nation's population. If conducted well, they could also raise expectations of a better justice system in Cambodia.

For the UN, the trials would further reinforce an international movement to punish, or at least expose, cases of major human rights violations.

"Brother No. One" in the Khmer Rouge, Pol Pot, died in 1998 without facing justice. Many of his comrades still live freely in the country. Only two are locked up. It could be difficult to bring stronger rule of law to a country already suffering from weak democracy if these men are allowed to avoid trial.

The international community had to push Cambodia's government to start these trials. They'll probably need to keep pushing.