Lasting peace demands justice. But the demands of justice can sometimes block peace. That has been the dilemma facing the International Criminal Court (ICC) since it began work six years ago. Tasked with the noble mission of trying war criminals, its efforts have also been a powerful disincentive to the world's worst leaders to end their repressive rule and open themselves to arrest. Nothing has made that more clear than ICC prosecutor Luis Moreno-Ocampo's request on July 14 for an arrest warrant for Sudanese President Omar Hassan al-Bashir on 10 charges of genocide, crimes against humanity and war crimes in Darfur. Moreno-Ocampo claims that Al-Bashir, who warned against the move during a Khartoum rally (above), "personally instructed" his forces to annihilate three ethnic groups in Darfur. "His motives were largely political," said Moreno-Ocampo. "His alibi was a counterinsurgency. His intent was genocide." Human-rights groups applauded. Others, including Western diplomats and governments in China and Africa, warned that the indictment risks prolonging, even exacerbating, the conflict in Sudan, which has already cost 200,000 lives and displaced 2.5 million people. Speaking for the African Union, Tanzanian Foreign Minister Bernard Membe told Agence France-Presse that if Al-Bashir is arrested, Sudan will face "a power vacuum . . . that risks military coups and widespread anarchy reminiscent of . . . Iraq."

The choice is between idealism and pragmatism. In Uganda, the ICC chose idealism and issued an arrest warrant for notorious rebel leader Joseph Kony, who then refused to sign a peace agreement until the warrant was lifted. In Zimbabwe, the court chose pragmatism, responding to queries on whether it plans to pursue President Robert Mugabe by saying it has no authority over the country as Zimbabwe never signed the Rome Statute, which established the ICC. This is disingenuous. Sudan hasn't signed the treaty either, a snag overcome when the U.N. Security Council referred the situation in Darfur to the ICC — something it could do with Zimbabwe. As ever, justice and peace are both prisoners of politics.