Section 197 of the 1979 constitution provides for establishing, equipping, and maintaining an army, a navy, an air force, and "any other branches of the armed forces" deemed necessary for defending against external aggression, for ensuring territorial integrity and security of the nation's land, sea, and airspace, for suppressing insurrection and aiding civil authorities when so directed by the president, and for performing other such functions as may be legally prescribed. The president, as commander in chief of the armed forces, is empowered to determine their operational use and to appoint the chief of the Defence Staff and the heads of the military services. Section 265 authorizes the president, subject to parliamentary action under certain conditions, to issue a proclamation of emergency only when the federation is at war, in imminent danger of invasion or involvement in war, in cases of natural disaster or an actual or imminent breakdown of public order and public safety.

The regime of General Muhammadu Buhari (which held power for twenty months from December 1983), in Decree Number 1, suspended and modified parts of the constitution to empower the FMG to issue decrees signed with the force of law. It also vested all executive authority in the head of the FMG, who exercised it in consultation with the Supreme Military Council (SMC). The SMC was composed of the head of the FMG as president of the council the chief of staff, Supreme Headquarters the minister of defense the chiefs of the army, navy, and air staffs the general officers commanding the four army divisions the commander of the Artillery Command the attorney general the inspector general of police six other appointed senior military officers and other members that the SMC might appoint. Its principal functions were to determine national policy on major issues and on all constitutional and national security matters and to appoint and to ratify appointments of top government, military, and public officials.

A National Council of State, composed essentially of the same officials as the SMC except for the line military commanders, was also established. Finally, Decree Number 1 provided for a National Defence and Security Council which, under the direction of the SMC, was responsible for matters of defense and public security. This council, which replaced the National Defence Council of the Second Republic, had as its members the head of the FMG as chairman the chief of staff, Supreme Headquarters the ministers of defense, of external affairs, and of internal affairs the three service chiefs of staff the director general of the Nigerian Security Organization the inspector general of police and others appointed ad hoc by the head of the FMG.

After ousting Buhari on August 27, 1985, General Babangida issued Decree Number 17, amending Decree Number 1 to establish the institutional basis of his regime. In place of the title head of the FMG, Babangida assumed the new dual title of president and commander in chief of the armed forces. A chief of General Staff, General Staff Headquarters, 9e2 , replaced the chief of staff, Supreme Headquarters the minister of defense was also chairman, Joint Chiefs of Staff. Buhari's Federal Executive Council was replaced by the Council of Ministers. The Armed Forces Ruling Council (AFRC), which replaced the SMC, originally had an enlarged allservice membership of nearly thirty, consisting of the same functional posts as the SMC plus the flag officers commanding of the Eastern Naval Command, the Western Naval Command, and the Naval Training Command the air officers commanding the Training, Tactical Air, and Logistics commands and twelve other appointed senior military officers. In February 1989, however, Babangida reconstituted the AFRC with only nineteen members. The National Council of State (thus renamed) and the National Defence Council and National Security Council, separated into two bodies, were retained. In the December 1989 government reorganization, Babangida assumed the defense portfolio but assigned the functions of chairman, Joint Chiefs of Staff, to the chief of army staff (see fig. 14). In September 1990, the Supreme Headquarters was replaced by the Defence Headquarters, and largescale reassignments and retirements of senior army, navy, and air force officers occurred. Babangida simultaneously relinquished the post of minister of defense to General Sanni Abacha, who also assumed the new position of chief of Defence Staff.

Figure 14. Organization of the Ministry of Defence and of the Armed Forces, 1990

Data as of June 1991