Sudan gave African Union troops a one-week ultimatum to accept a deal that would block a proposed U.N. peacekeeping force in Darfur or else leave the war-torn region, a step that would likely worsen the world’s worst humanitarian disaster. The deadline announced Monday escalates Khartoum’s standoff with the United Nations over Darfur to a key crisis point, pitting Khartoum’s determination to resist possible war crimes investigations against the U.N.’s appetite for a new, rough peacekeeping mission. Full Story