Between 1976 and 1986, internal security responsibilities in Nigeria were divided among the NSO, a central state security organ reporting to the president the Ministry of Internal Affairs the national police force and the Ministry of Defence. As noted, the army was called upon to suppress domestic disorders on several occasions.

Intelligence Services

The NSO was the sole intelligence service for both domestic and international security during its ten-year existence. It was charged with the detection and prevention of any crime against the security of the state, with the protection of classified materials, and with carrying out any other security missions assigned by the president. Under the Buhari administration, the NSO engaged in widespread abuses of due process, including detention without charge and trial, arrests without pretext, and wiretapping.

The NSO's performance was bluntly criticized after the 1980 uprisings by the Maitatsine movement. It had penetrated the movement but failed to prevent it from instigating bloody riots.

Fulfilling one of the promises made in his first national address as president, Babangida in June 1986 issued Decree Number 19, dissolving the NSO and restructuring Nigeria's security services into three separate organizations under the Office of the Co-ordinator of National Security. The new State Security Service (SSS) was responsible for intelligence within Nigeria, the National Intelligence Agency (NIA) for foreign intelligence and counterintelligence, and the Defence Intelligence Agency (DIA) for military-related intelligence outside and inside the country. This reorganization followed a formal investigation of the NSO by former director Umaru Shinkafi.

Notwithstanding this rationalization and depoliticization of the national security services, they remained deficient in intelligence collection and analysis capabilities they also were poorly equipped to counter security threats, such as covert foreign operations, dissident movements, coup plots, and border violations. The integrity of the new agencies also eroded after the prosecution in 1988 of the director of the DIA and the deputy director of the SSS, for the 1986 murder of Newswatch publisher Dele Giwa.

In the government reshuffle of December 29, 1989, Vice Admiral Patrick S. Koshoni, chief of naval staff since October 1986, became head of the National Commission for the Reorganisation of Internal Security the Office of the Coordinator of National Security was abolished and the SSS and NIA remained independent agencies directly responsible to the president.

Data as of June 1991