Next Monday, almost a year after his arrest by British law enforcement authorities, former Chilean dictator Augusto Pinochet's extradition trial will begin in London. In the months since his arrest, the intense debate about his case has, interestingly enough, not centered on whether he did what he is accused of. Indeed, the gravity of these accusations has been almost forgotten amid the flurry of debate about the case.

Shortly after overthrowing Chile's democratically elected government in 1973, forces under Pinochet's command began to obliterate vast segments of the country's population. Thousands of people whose political, ethnic or religious backgrounds suggested that they might oppose Pinochet's junta were abducted by the military. Thousands more were abducted by paramilitary groups controlled by Pinochet's aides. Once in custody, victims were often tortured or sexually assaulted. While some lived to tell about it, over 4,000 people were either killed by Pinochet's forces or disappeared while in custody. Although the missing are still technically victims of kidnapping, one can only assume that they are dead. The criminal activity of Pinochet's forces knew no borders. His government's secret police, the DINA, assassinated prominent Chileans in Washington and Buenos Aires, and tried unsuccessfully to kill Chileans in Rome and Madrid.

Over the past several years, Spanish lawyers have presented an investigating magistrate with reams of evidence documenting that forces under Pinochet's command were responsible for acts of murder, torture, kidnapping and international terrorism. Moreover, they have presented the Spanish magistrate with newly available evidence showing that this campaign of terror was directed by the dictator himself. In response, the magistrate issued indictments against Pinochet, and put out the international arrest warrant that led to his detention.

These days, almost a decade after Chile's dictatorship came to an end, even Pinochet's defenders rarely deny that his regime is responsible for these atrocities, or that Pinochet himself directed his government's reign of terror. Instead, they ask why Spanish courts should be trying Pinochet. Put another way, they ask why foreign nations shouldn't be forced to accept the way that Chilean authorities resolve--or don't resolve--these charges.

Simply put, the lawyers for Pinochet's victims got indictments in Spain, and not Chile, because the general was still a powerful man up to the day of his arrest. Before resigning his dictatorial post in 1990, Pinochet decreed that he and his subordinates would be immune from prosecution for their crimes, even after he stepped down. He then used his authority while Chile's constitution was being written to ensure that this decree could never be repealed without his consent. Since 1990, Chilean courts have consistently been forced to uphold this immunity decree; cases against Pinochet in Chilean courts have all been thrown out before going to trial.

Pinochet's victims therefore went to Spain to search for the justice that was impossible to obtain in Chile. In asking another nation to prosecute, the victims were simply asking that Spain exercise a long recognized right--and obligation--under international law. Legal scholars have long held that customary international law permits any nation to try those who, like Pinochet, are accused of genocide or international terrorism. In the event that the nation where the acts occurred proves unable or unwilling to do so, third party nations have the right and obligation to prosecute.

This principle is not some carte blanche for nations to prosecute foreign leaders. It applies specifically and only to cases like Pinochet's, when somebody who has committed truly terrible crimes on a massive scale would otherwise avoid the reach of justice. This principle has been accepted and applied by prestigious national courts in the past. The Israeli supreme court did so when it tried the Nazi war criminal Adolf Eichman. American courts also accepted the principle when they extradited John Demjanjuk to Israel for trial as a Nazi war criminal.

The ideas on which the Spanish case against Pinochet are based are not just widely accepted, they are also logical. If, as Pinochet's supporters argue, third party nations should not be able to try Pinochet, then the world would be made subject to his decree of immunity. Foreign nations would defer charges to Chile, which would do nothing about them, and Pinochet's victims would be left without recourse. If taken seriously, Pinochet's argument would mean that any criminal leader could avoid all consequences of their actions, simply by granting him or herself immunity. If Slobodon Milosevic decides to grant himself immunity, should the world really have to respect that? Had Hitler granted Nazi leaders immunity, should the world really have had to respect that?