The Sudanese government and southern rebel groups signed an agreement Sunday after three years of negotiation. The agreement seeks a comprehensive settlement after 21 years of fighting by allowing southern rebels to share power and oil wealth with the Khartoum government. Secretary of State General Colin Powell told an audience of several thousand at the signing ceremony that the agreement was historic and stressed that the two sides must uphold their ends of the bargain. He also urged Khartoum to move swiftly toward peace in the western region of Darfur. The deal includes a number of measures that are politically sensitive and may prove difficult to implement. It entitles the southern region to organize an autonomous government and constitution and get a share of Sudan’s oil revenue. It calls for the integration of the rebel Sudan People’s Liberation Army into the central government’s military. It makes John Garang, the U.S.-educated rebel leader, first vice president in a new Sudanese government. It also provides for a referendum after six years that would give the south a chance to declare its independence. We’ll have more on this story later in the program.