In Germany last week, 89-year-old John Demjanjuk, a former Ohio autoworker who came to the United States in 1952, lay on a stretcher and listened to the accusation against him: that he was an accomplice in the murder of at least 27,900 people who died at the Sobibor concentration camp while he worked there in 1943. The trial, now on hold because of Demjanjuk's ill health, is the latest example of holding individuals accountable for the crimes of the murderous regimes they served. Law was first used to deal with such crimes in the post-World War II tribunal in Nuremberg, Germany, where Allied judges tried 22 Nazi leaders for the Third Reich's atrocities. Demjanjuk was allegedly a relatively low-level perpetrator, but today's defendants include once-powerful figures and even sitting heads of state. The international tribunal for the former Yugoslavia has finally gotten its hands on Radovan Karadzic, the man believed responsible for the Srebrenica massacre, 14 years after his original indictment, and the International Criminal Court in the Hague is going after Sudanese President Omar Hassan al-Bashir on charges of war crimes and crimes against humanity in Darfur. Few today question whether a country's leaders should be held personally responsible for state crimes committed on their watch. Still, the methods remain controversial. The United States deported Demjanjuk to Germany and supports the Yugoslavia tribunal, but it is unwilling to join the ICC, fearing that American soldiers -- or leaders -- might one day find themselves in the dock. War-crimes trials mainly happen in international courts. 1. International trials are only a small subset of the many prosecutions going on today. True, the courts for the former Yugoslavia and for Rwanda have convicted dozens of top perpetrators, and the ICC is tackling cases from four African countries. But their resources are limited. Most trials take place in domestic courts, or in 'hybrid courts' that combine local and international lawyers and judges, bolstering weak judicial systems and adding a measure of impartiality. In Cambodia, a hybrid court known as the Extraordinary Chambers in the Courts of Cambodia, assisted by the United Nations, is completing its first trial of those responsible for the 'killing fields' 30 years ago. Similar courts have been employed in Sierra Leone, Bosnia, Iraq and East Timor. More controversially, some national judges and prosecutors, such as Spanish Judge Baltasar Garzon, have used the idea of 'universal jurisdiction' -- that some crimes are so heinous any country has a right to prosecute them -- to investigate foreign leaders for crimes committed abroad, particularly if they might otherwise escape accountability. No need for trials. It's obvious these guys are guilty. 2. Winston Churchill agreed with Joseph Stalin that the best way to deal with Nazi leaders was to shoot a few of them. A trial implies the possibility of acquittal. Do we really want to risk letting mass murderers go free? The same argument has been raised in the case of Khalid Sheik Mohammed, the self-proclaimed mastermind of the Sept. 11, 2001, terrorist attacks, who may soon stand trial in New York. Yet our legal system is predicated on the belief that even bad guys get their day in court. Law is fundamental to functioning societies. After nations have been torn apart by conflict, legal proceedings help re-establish the rule of law. Revenge tends to breed further violence, but transparent trials of key individuals help to prevent entire groups from feeling blamed. And courts establish factual records, such as Nuremberg's 22-volume trial transcript, that counter the denials of those who would rather believe the unthinkable didn't happen in their own backyards. It's never too late. 3. This is a tough one. It's one thing to see former leaders -- Slobodan Milosevic of Yugoslavia, say, or Hermann Goering in 1946 -- stripped of their arrogance and trappings of power at a time when many of their victims are alive to witness justice. But it's harder -- even for me, the daughter of a Holocaust survivor -- to gain much satisfaction from the possible conviction, 60 years after the fact, of a frail 89-year-old. In Demjanjuk's case, perhaps too much time has passed. But context also matters. The aged defendants in the Cambodia trials, for example, were key actors in that nation's horrors and are the first to be tried for their country's crimes; their prosecution marks the beginning of justice, not, as in Demjanjuk's case, its last gasp. Yet even a delayed trial such as Demjanjuk's can serve to educate a new generation. Justice and deterrence, too, argue for prosecution: For crimes as heinous as genocide, no one should be able to escape accountability, ever, and future perpetrators should know their guilt will never expire. Trials help foster reconciliation at home but don't matter much elsewhere. 4. In the case of international tribunals, at least, the reverse is more likely the case. It wasn't the Nuremberg tribunal that led Germans to face their history; at the time, the trial wasn't very popular in Germany. It took education, social change and time before a new generation of Germans was able to look more honestly at the past. The tribunal for the former Yugoslavia, too, is widely resented at home. Mass crimes require popular support -- be it active involvement or passive complicity, such as accepting a government's racist agenda -- and those views don't change overnight. Victimized groups will be pleased at the verdicts of international tribunals, which are often less biased than those of domestic courts, but at least in the short run, such trials are unlikely to cause major changes of heart in the countries for which they're created. Trials may have a broader deterrent effect, however. Though international justice is too new for definite conclusions, leaders and foot soldiers are starting to be concerned about international courts. Human Rights Watch has reported that an Afghan warlord specifically warned his troops against committing war crimes because of the danger of international prosecution. The trial of a Congolese rebel leader accused of recruiting child soldiers has reportedly affected the behavior of local fighters. Even the indignant response to Bashir's indictment among some African and Arab League leaders suggests they take the ICC's actions seriously. The more consistently international prosecutions happen, the more meaningful their deterrence effect is likely to become. You can't get a fair trial in an international court. 5. It's true that international courts don't adhere to the procedural standards applied by U.S. courts. But neither do European courts. Jury trials are not the norm in Europe; nor are the hearsay rules we're accustomed to seeing on 'Law and Order.' Yet Americans can be tried in foreign courts if they commit crimes overseas. In fact, international tribunals have developed extensive rules of procedure based on a combination of many countries' legal practices. Fear of a malicious prosecutor is equally misplaced; prosecutors and judges in international tribunals tend to be respected jurists, and the ICC statute includes limits on the court's power to initiate prosecutions -- limits drafted in part by the United States, which was active, 11 years ago, in creating the court it has yet to join. Belinda Cooper, the editor of 'War Crimes: The Legacy of Nuremberg,' is a senior fellow at the World Policy Institute and an adjunct professor in New York University's global affairs program. 