(a) Britain introduced Indirect Rule in Nigeria as a result of the following factors:
(i) Lack of adequate personnel; Lord Frederick Lugard decided to adopt this system in Nigeria due to lack of British personnel to effectively administer the vast area of Nigeria. It was argued in some quarters that few Europeans were ready to come to West Africa at this time due to the presence of insects like mosquito and tsetse flies.
(ii) Insufficient fund: Britain did not want to involve itself in an unnecessary financial responsibilities of its colonies, after involving itself in many wars earlier e.g. American war of independence.
(iii) The success of this system in some countries of the world: The system of indirect rule was successful in countries like Uganda, India, etc. So, Britain felt that, the success of it in these countries will also mean the same here in Nigeria.
(iv) Preservation of customs and traditions of the people: The argument advanced by Lord Lugard was that the system would help to preserve the customs and traditions of the people of Nigeria. This was why he made use of the traditional rulers and their systems in place.
(v) The atmosphere was favourable: The system was successful in Northern Nigeria because the political atmosphere was stable and favourable. The Emirs were highly respected by their people and if Britain should displace the Emirs from their position, it might attract the wrath of the people.
(vi) Economical to operate: This system was economical to operate. Britain would have expended a lot of money on paying personnel or officials to run the affairs of Nigeria as a whole.
(vii) Language barrier: This system reduced the problem posed by language. English language was not a language spoken by Nigerians and so adopting an indirect approach in administration would reduce this problern.
(viii) Large expanse of land: The large areas of Nigeria contributed to the adoption of indirect rule system.
(ix) Involving traditional rulers: Lord Lugard saw the need of bringing in traditional rulers in the art of administration, isolating them might not produce a good and stable administration.
(b) The system of Indirect Rule was successful in Northern Nigeria, partially successful in the West and a complete failure in the East, as a result of the following:
(i) Appointment of Warrant Chiefs: The Obiship institution was not properly defined in the East the British officials had to appoint Chiefs, otherwise known as Warrant Chiefs, without consulting the people. These Chiefs were highhanded and not acceptable to the people. Most of their activities were outrageous and that was one of the causes of Aba women's riot of 1929.
(ii) Political administration practised: Igbo political system is based on decentralization of administration and cannot accommodate the indirect rule system which could mostly work on a centralised administration.
(iii) No properly defined system of Taxation: The system of tax payment and collection was not properly defined in the East as compared to that obtainable in the Hausa/Fulani political system. These inadequacies made the execution of some projects by the British impossible.
(vi) Non-inclusion of educated elites: The educated elites were not included in the administration. Instead, the British preferred the illiterates as warrant chiefs and this sparked off protests and rejection of the system by the elites.
(v) The importance of education: The educated citizens in the east were able to question the essence or relevance of an alien system that had no moral justification.
(vi) Religion: Christianity was a dominant religion in the east and had a western democratic orientation. It helped in bringing down indirect rule system in the west.
(vii) Small size of the units: The units in the igbo political system were too small compared to other systems e.g. the Hausa/Fulani emirate system.
(viii) The people were not submissive: Their failure to submit to the rulers was because their rulers were imposed on them. Igbo political system is egalitarian and decentralised, and so they detest authoritarianism.
(ix) The system was an intruder: Since the people's tradition was abused and neglected, this led to the failure of indirect rule system.