After a careful, first reading many of the points on the 'human terrain' or context for Boko Haram have been made here. I would contend with additional insight along the way
The first thing you need to understand about Nigeria, is that it is an artificial construct, created by the British to reduce administrative expenses.

The area called Nigeria has been inhabited by several ethnic groups with very different cultures, over a period of thousands of years. In Nigeria's South West, the Benin Empire and the Yoruba Kingdoms were predominant. (A distinguishing characteristic of the Benin Empire was that they refused to sell slaves to Europeans). In the South East, the Igbo were organised into villages, and in most cases they didn't have central leadership figures (they tended to be more consensual). There are other ethnic groups in the South that shared some of the characteristics of the Igbo and the Yoruba.

Slavery was the most significant event to occur in Southern Nigeria before British rule. The impact of slavery on African Americans has been extensively studied, but the impact of slavery on the African psyche has been less studied. I believe that corruption and inter-ethnic antagonisms are the biggest legacies of slavery (slavery was a deeply corrupting, soul-destroying business and most slaves were the victims of wars).

(These are merely my uninformed views).

In Northern Nigeria, Islam had a very long history. There were two major centers of Islam, the Hausa States and the Kanem Bornu empire. In between the Islamic North and the South, there were the Middle Belt people like the Tiv, the Jukun, the Berom and the Igala. The Islamic North hasn't always had a good relationship with these people - the North raided the Middle Belt to procure slaves to sell to the Arabs.

The most important Islamic figure in Islamic Northern Nigeria was Uthman Dan Fodio. Dan Fodio established the Sokoto Caliphate in the late eighteenth century / early nineteenth century. Before Dan Fodio, Islam tended to be restricted to the courts of Muslim rulers and the serfs practiced the local animist religion. Dan Fodio's greatest legacy was the jihadist tradition / less tolerant form of Islam practiced in Northern Nigeria. (In Nigeria's South West, the Islamic tradition is much more tolerant, because it was introduced by traders from the Mali Empire - you have many instances of Muslim wives / Christian husbands and vice versa in South West Nigeria).

The British originally ruled two colonies - the Southern protectorate and the Northern protectorate. In 1914, Lord Lugard (who cut his teeth in India), amalgamated the North and South protectorates and his fiance coined an expression "Niger Area" - Nigeria to describe this colony.

Northern Nigeria was ruled very differently from South Nigeria. Paradoxically, British rule enhanced the power of Northern emirs (local sheiks), the reverse was the case in the South. Lugard adopted a system called indirect rule from India. Under indirect rule, the British ruled through the established traditional structures. It worked splendidly in Northern Nigeria, but it had disadvantages:

1. Western education was not encouraged, because missionaries were the primary agents. Naturally, the emirs were not too happy with that.
2. The British put non-Muslims under emirs, this led to tensions.
3. At the end of the colonial era, the North was far behind the South, and that gap is yet to be bridged.

The British still needed low-level clerks, administrators and railway workers, so they had to bring them over from the South to the North. Their higher living standards, attracted jealousy and the 1953 riots in Kano was one of the first outbursts. There was also another movement led by Aminu Kano, which opposed the entrenchment of the existing class structure by the British and argued for the emancipation of the talakawas (commoners).

Nonetheless, in 1960, this entire area was granted independence by the British. A northerner was selected as prime minister, the president came from the South East, and the South West formed the opposition. A disagreement between the Obafemi Awolowo (the leader of the opposition) and Akintola (the Western premier), triggered Nigeria's first crisis. This led to a coup by officers from the South East in 1966. The major victims of the coup were from the South West and the North (Ahmadu Bello, the major Northern figure). This triggered a counter-coup by Northern Military officers, led by Murtala Muhammad and Yakubu Gowon. After the coup succeeded (so the story goes in Southern Nigeria), Murtala Muhammad hoisted the flag of Arewa and was ready to secede from the rest of Nigeria (until Western diplomats and Oil and Gas executives convinced him to do otherwise).

The Northern counter-coup in 1966 triggered a violent reaction in the North against South Easterners (Igbos). These massacres led to the Nigerian Civil War, in which most of Nigeria's future military rulers played a role.

These men (Obasanjo, Babangida etc) , may be the last true believers in Nigeria's unity.

Oil was discovered in the Niger Delta in 1956. In the run up to independence, the Willink Commission made recommendations on how the Niger Delta should be treated in an independent Nigeria - they were never followed. Western Oil companies began their operations with scant regard for the environment - massive gas flaring and oil spills were neglected. The killer blow was the Land Use Act of 1978. Government had the right to confiscate your land and hand it over to an Oil and Gas company for an oil mineral lease or an oil prospecting lease and compensate you only for the cost of your property on the land (i.e. 0.50 naira for every stick of cassava).

The difference in living standards between employees of Oil and Gas companies and natives triggered resentment (especially when they had to deal with gas flares 24/7). Saro-Wiwa protested against this in Ogoniland, he was hanged by Abacha, the Kaiama declaration was written in 1999, and hell was let lose.

Meanwhile, the Northern elite continued to consolidate their hold on power (Nigeria was ruled by Northerners from 1960 - 1976, 1979 - 1999). More money was allocated to Northern Nigeria than to Southern Nigeria, and while this was resented by the South, it did not lead to any appreciable improvement in the standard of living of Northerners. The talakawa agitated, but they were put down by the Northern elite.

In 1982, our oil revenues could no longer meet our budgetary commitments (we learned very bad habits during the oil boom era). Austerity measures were introduced, and that led to a military coup in 1983 and another in 1985. Nigeria was forced to adopted IMF/World Bank structural adjustment programmes (Reagan/Thatcher reigned supreme then). We were mandated to cut spending on social programmes and embark on privatisation. The result was a hollowing out of the middle class and a massive drop in quality of health care / education.

(Sometimes, I wonder why our politicians listen to the West. In the 70's it was all about industrial development and infrastructure. In the 80's it was reduce spending on social programmes. Today it is increase spending on social programmes and some BS on millennium development goals. Anyway that is a topic for another day).

Sharia has always been a hot topic in Nigeria (at least since the constituent assembly in the 1970's). The British left a confused situation in which elements of Sharia were recognised and the role of Muslim traditional rulers were affirmed. The level of dissatisfaction with the Northern elite pushed them to adopt Sharia in twelve Northern States as from 1999 (more in theory than in practice). It was a cynical ploy to cement their relationship with the masses and to distance and distinguish themselves from the Christian-led Obasanjo regime.

However, there are true believers like Boko Haram, who can see beyond the cynicism of the North elite and want the real thing. They have the support of the masses and for the first time in my life, Nigeria's Northern elite are being openly and violently challenged by their people.

Boko Haram is many things, it is a:

1. Jihadist movement/terrorist organisation.
2. A vehicle to challenge the dominance of the Northern elite.
3. A source of identification for many unemployed, under-educated Northern Muslim youths.

These factors will put pressure on the Northern elite to dissociate/distance themselves from Abuja and hence impact on Nigeria's unity.

Meanwhile, Boko Haram taps into another source of tension, the rapid expansion of Evangelical Christianity in Northern Nigeria. This has led a series of conflicts and the prospect of the World's first Evangelical Christian militant organisation Akwat Akwop.

In summary, Nigeria is a mess. There is a steady supply of unemployed young men with grievances. I can see a proliferation of militant groups in the future (Christian militants in the Middle Belt, "Biafran" militants, Yoruba militants, Niger Delta militants). It will only take one successful Boko Haram operation in Lagos to trigger an ethnic war between the Hausa-Fulani / Kanuri and the Yoruba.

We need to sit down and renegotiate the basis for nationhood - and time is running out fast, a generation with no memories of the Nigerian Civil War is assuming positions of leadership.