In the discussion of the factors responsible for military intervention in politics in African countries and Third World countries in general, two main schools of thought have developed. These two models are the internal characteristic model and the politicization model. The internal characteristic model was propounded by Morris Jamowitz. In his book, Jamowitz has argued that one can explain military intervention in politics mainly by reference to the internal structure of the military. In other words, the social background of the officers, the skill structure and career lines, internal social cohesion, the cleavages, professional and political ideology within the military are important factors which help to explain direct military intervention in politics. Samuel Huntington, has put forward what is now regarded as a second school of thought. He has condemned the first school of thought as baseless and has contended that “military explanations do not explain military interventions and that the most important causes of military intervention in politics are not military but political”. This in Huntington’s view is because military intervention in developing countries is only one specific manifestation of general politicization of social forces and institutions. Societies where most social forces and institutions are highly politicized have political clergy, political universities, political bureaucracies, political labour unions, political corporations and of course political armed forces. All these specialised groups tend to become involved in political issues which affect their particular interest or groups and also in issues which affect society as a whole. As a result the whole society is out of joint, and no political institution or group of political leaders is recognised or accepted as the legitimate intermediary to moderate conflicts, no agreement exists among the groups as to the legitimate and authoritative methods of resolving conflicts.” However, in discussing the factors responsible for military intervention in politics, a combination of the two schools of thought is carried out. Military rule is generally regarded as an aberration. A generally accepted political system is such a system that is governed, directed and controlled by a civilian political class which has been recruited by popular choice to the decision-making structures of the state. This conception is even held by the military itself. However, they still catapult themselves into political power. The reasons for such involvement in the political process include the following:

Corruption among the civilian rulers may lead to a military intervention in politics. The African governments embarked upon independence lacking, besides internal cohesion, essential knowledge of governmental affairs and most of the essential institutions that form the basis of any stable government. According to a radio broadcast on the first military coup in Nigeria, one of the reasons given for the coup was “to bring to an end gangsterism and disorder, corruption and despotism. It ended; my compatriots, you will no longer need to be ashamed to be Nigerians.” The failure of the existing political institutions to establish a legitimate base and to win the respect and support of the powerful groups within the state may engineer a military coup. Thus, far from meeting widespread opposition to its intervention, the army may be welcomed as a means of ridding the state of the old corrupt and inefficient politicians.
Sources: https://www.cosmoworld.com.ng/theories-of-military-intervention/