The countless victims of Sudan's dictator can draw comfort from one fact: international justice has yet to catch up with Omar al-Bashir but he is the only head of state who must worry about being arrested whenever he travels abroad. The saga over his indictment by the International Criminal Court dates back to the outbreak of rebellion in the Darfur region of Sudan in 2003. al-Bashir responded to the challenge with utmost ferocity, arming and recruiting militias from tribes friendly to his regime and turning them on ethnic groups that supposedly backed his enemies.The result was a brutal scorched-earth campaign in which countless villages were razed and their terrified inhabitants herded into squalid camps.At least 2million people - that's a third of Darfur's population - were driven from their homes. Another 300000 died in one of the bloodiest conflicts of the century.The question of how to hold Bashir accountable has been bitterly controversial. The Western powers chose to refer the war in Darfur to the ICC for investigation by its chief prosecutor.This was not as simple as it might appear. Sudan did not sign the Rome Statute that created the ICC, so the court had no jurisdiction over Darfur. The US, UK and France overcame this by securing the passage of UN Resolution 1593, which referred the "situation in Darfur" to the ICC in 2005.There followed four years of investigation by the court's chief prosecutor, culminating in the ICC's "pre-trial chamber" in 2009 issuing an indictment and arrest warrant.al-Bashir was charged with "intentionally directing attacks against a civilian population", involving "pillage as a war crime", along with "extermination", "rape" and "forcible transfer". He was indicted on two counts of "war crimes" and five of "crimes against humanity".At this stage, however, the judges rejected the prosecutor's attempt to charge him with "genocide", arguing that the crucial question of whether al-Bashir had intended to eradicate a given ethnic group was unproved. Under the Genocide Convention of 1948, the crime is defined as an act "committed with intent to destroy" a specific group of humanity.But Luis Moreno-Ocampo, then the ICC's chief prosecutor, did not give up. He argued that Bashir's decision to put millions into squalid, disease-ridden camps showed intention to wipe them out.In 2010, the judges changed their minds and agreed: they issued a new arrest warrant for Bashir, adding three charges of genocide.al-Bashir became the only head of state yet to be formally accused of genocide. Ever since, he has carried the equivalent of the Mark of Cain.All 123 members of the ICC are legally obliged to arrest him, including 34 African states. Some African presidents appear to believe the indictment is a Western plot. In solidarity with Bashir, they have shown themselves willing to ignore legal obligations...