Why has the Nigerian military struggled within its contribution to counter insurgency, and what are the underpinnings of that contribution? This is the central question addressed by this research PhD, as an original contribution to academic knowledge. The thesis begins by examining the broader discourses, with one overarching set of findings: the military contribution to counter-insurgency is, ab initio, fraught with problems and is a difficult contribution to make effectively and with readily demonstrable results. This for the most part is the case for militaries everywhere, moreover. Part of this difficulty is down to the nature of insurgency as irregular warfare. That the Nigerian military has struggled within its contribution to counter-insurgency therefore is not, in itself, unique. What is unique, and where this project makes an original contribution to academic knowledge, are the processes that underpin the Nigerian military’s own contribution to counter-insurgency, from its formative years as a professional fighting force, to date. Consequently, four premises, supported by evidential data, and with field and theory-driven analysis, underpin the thesis’ research-based argumentative response to the central question. The first premise of the central argument holds that the Nigerian military’s identity crisis, emergent from a hasty institutional transfer process from the British, contributed to institutional isomorphism. This is a process whereby an organization B, modelled after another, A, in order to reduce uncertainty, limits and selectively adapts change. The Nigerian military’s failure to re-interpret its internal function left it as a “coercive institution” of the state and, furthermore, left it even more internally involved than was the case during the colonial administration. With indiscipline already an issue within the institution, this political meddling, a coup culture, and a neglect of professionalization, will further undermine the military’s legitimacy and will damage the civil-military interface. The second premise is that strategic culture of the post-civil war era meant the military saw a regional peace support role for itself between the late 1980s and the turn of the century; and before that, in the 1970s, perceived the main threat to security as external and largely Francophone. Neither posture encouraged the need to diversify the military function to accommodate a counter insurgency culture. Consequently whereas there already was recognition within the Army’s school of infantry, as at 1978, that counter-insurgency required development, this development will be stifled over the decades. Third, doctrinally — both in codified and in uncodified form — the Nigerian military persistently failed to develop theory and practice suitable for counter-insurgency. The military’s doctrine drew too heavily from Western interpretations to accommodate its own experiential learning and the local operational environment. The Nigerian military’s doctrine moreover, has been demonstrably difficult to change, in situ, during a campaign. This is in stark contrast to Boko Haram’s military doctrine, and its adaptability, examined in the thesis. The three previous premises therefore, connive to give the lie to the notion that the Nigerian military, in its operational contribution to COIN, should have been more effective. If anything they lend explanatory power to why it seems too much, in too little time, is now expected of operations by a military that culturally, institutionally, and doctrinally, has failed to purposively prepare for this forme de guerre. Still, at the operational level of war, there has been some progress. JTF ORO had its challenges, and at times struggled; but certain lessons can be taken, in the area of joint and multi-agency operations, from that phase of the Nigerian military’s counter-insurgency. By evaluating these four underpinning premises, by supporting them with evidential data, and by structuring all four areas of thought into a coherent narrative on Nigerian military counter-insurgency, this study therefore constitutes an original contribution to military and academic knowledge.