 He played an important role in the coup that ousted President Shehu Shagari and the Second Nigerian Republic on 31 December 1983 and brought General Muhammadu Buhari to power.Following the coup he was proposed as overall head of Intelligence, with the support of Chief of Army Staff Ibrahim Babangida, but the appointment was opposed by Buhari.Buhari confirmed Shagari's appointee Muhammadu Lawal Rafindadi as director of the National Security Organization (NSO), and dismissed Aliyu from the DMI, replacing him with Colonel Halilu Akilu.