Already the UN has been receiving reports of atrocities, looting of UN warehouses, revenge and summary executions in the streets of Mazar. The Tajik forces now commanded by Mohammad Fahim, successor to Ahmad Shah Masood, have trained a force of 1,000 paramilitary police to control Kabul - but keeping control of the sprawling ruin of a city with more than two million desperate inhabitantsseems close to a mission impossible. An urgent question now for America and its allies is the whereabouts of Osama bin Laden and his immediate lieutenants, and the potential for revenge attacks by al Qaeda.