Why the Biafran war was prolonged.

The war went on much longer than either side expected. There were important reasons for this, Biafrans were determined to maintain their independence and this made them resist for 2 years.
 
There was a strong military strategy used by the Biafra army to defend themselves.
 
The Ibo fear of genocide made them more determined to foght. This factor not only stiffened Ibo resistance but it attracted some international support for Biafra.
 
Support from the capitalist oil producing companies of USA and France.
 
Originally Ojukwu's forces received enormous support and welcome from the civilians.
 
The recognition of Biafra by 4 African states gave her moral courage to fight on. Among the African states that recognized Biafra were: Tanzania and Zambia for altruistic and humanitarian reasons; and the Ivory Coast and Gabon because of their strategic fears of an over-powerful Nigeria dominating West African politics and economic developments, and their willingness to do the bidding of France.
 
The enemies of a United and powerful Africa also extended support to Biafra e.g South Africa, Portugal, and Rhodesia
 
Yakoub's diplomacy whereby he first gave room for negotiations enabled Ojukwu to strengthen himself and light a prolonged war.
 
The Ibo had a number of engineers and artists who could produce locally manufactured guns, soap and bombs. This sustained Biafra during an economic blockade.
 
Strong commanders such as Ojukwu, colonel Hannibal and Achuzia enabled the Ibo to fight for long.
 
The Ibo were familiar with the terrain in which they fought.
 
Profits from oil products.
 
Support from France which wished to see the disintegration of Nigeria. France therefore provided arms to Biafra. French aid, motivated parity by a desire to secure exclusive rights over Biafran oil, and partly by a desire to break up powerful Nigeria and increase the relative strength of the francophile states in West Africa, was crucial from late 1968 in lengthening the war by more than a year, a period when France became Biafra's principal supplier of foreign currency for the purchase of arms and Other supplies. From September to October 1968 the Biafrans were supplied by France with up to 5000 tons of arms weekly.
 
Such aid at such a time was of major importance when oil fields which would have provided much foreign exchange fell into Federal hands early in the war, and much of Biafra's limited reserve funds were lost in dubious arms deals in which the Biafrans were duped. A further but less crucial factor was the limited help Biafra received from the colonial and white-settler regimes of Portugal, South Africa and Rhodesia, in the form of some weapons and a few mercenaries.
 
Obviously these regimes hoped to see the splitting up of independent Africa's most powerful nation. Of more use to Biafra were the night flights of Von Rosen, the Swede, into Uli airstrip to deliver arms and relief materials. Nor should it be overlooked that the skilled leadership of several Biafran officers, and their intimate knowledge of the terrain, helped to prolong the war. Then there was the ingenuity and resourcefulness of Biafran scientists and engineers who made guns and ammunition, designed makeshift refineries for vehicle fuel and manufactured soap and drugs. The Ibo elite were totally committed to Biafran war aims.

National Movements and New States in Africa