President Olusegun Obasanjo opened a conference to draft changes to the constitution on Monday with a warning that delegates should not question the fundamental unity of Nigeria. “The National Political and Reform Conference is not designed to dismember or disintegrate Nigeria,” Obasanjo told the 400 delegates assembled in the federal capital Abuja. Obasanjo is a retired army general who fought as a military officer against the attempt by the Igbo people of southeastern Nigeria to form the breakaway state of Biafra in the 1967-1970 civil war.