The recent kidnapping of 300 girls in northern Nigeria has rightly ignited a fresh firestorm of concern about Boko Haram. We must be grateful that the world's attention has turned to this crisis.

Tragically, however, Boko Haram has been slaughtering innocent people for a long time. Although many of the atrocities have made international news before, current events have cemented indignation. Some other incidents were either too obscure or too common to garner attention at all. In recent years, I have had Nigerian students who knew people killed in church bombings never reported in the West.

Although Boko Haram itself may date to 2002, similar violence was occurring in northern Nigeria in the 1990s. The fuller setting of regional violence, not my primary interest here, includes even conflicts in past centuries between the Hausa-Fulani and Middle Belt tribes, more recent conflicts between sedentary farmers and Fulani herdsmen, and other factors.

I should concede up front that I am no expert on African affairs, nor do I have special intelligence available to governments. What I can share are observations from spending 129 days over the course of three summers in northern Nigeria, and reports I heard from trusted friends there. Extremist violence dates far before 2002.

One Nigerian minister friend told me that he was in a particular northern city when supposedly spontaneous riots broke out. Aggressors already had mapped out where all the pastors lived, and went from one street to another killing them. He and his African-American wife and baby daughter hid under a table as rocks came through the window. Suddenly their Muslim neighbor turned the attackers away, crying, "This is a house of peace." That was why my friend was alive to tell me the story.

After I first arrived in northern Nigeria in 1998, a friend summarized his understanding of how the troubles of recent years had started. Some Muslim extremists, often recruiting unemployed and impoverished boys, initially attacked moderate Muslims. When they later began attacking Christians, moderate Muslims urged the Christians to stay out of the fight and let them take care of it. In time, however, the extremists provoked Christians into retaliating, very often leading to broader hostility between Muslims and Christians. My best guess is that extremists hoped to have influence far beyond their numbers by turning the communities against each other. Various informants also named politicians they believed were sponsoring the violence for political purposes, and countries they thought were funding it. Some named friends killed by the violence.

I cannot verify all the reports, but I do know that much of the sort of information now available about northern Nigeria was not getting out to the world at that time. The military president, Sani Abacha, kept control more efficiently than an open state could, but such control came with a price. One witness, for example, told me of a robber, now disarmed, gunned down by the police in front of her. More directly, I myself was present on the campus of the University of Jos on the morning June 2, 1998, when police with assault rifles chased students from their hostels. This information, however, was not circulated publicly.

Later that evening I was sitting with some prominent local people. Though unaware of what transpired earlier that day, some were arguing that public protests against Abacha's rule had become necessary; others objected that the protests would be crushed quickly with bloodshed. As it turned out, Abacha died within a week.

Despite Abacha's demise, the information released to international media often remained limited. This was probably partly to maintain control and diminish reprisal attacks, and partly for political reasons. Still, in the years that followed I continued to receive reports from local friends about massacres. During one riot one of my students was among those under siege for two days in a church with a corpse and no water. Sometimes terrorists arrived in military or police uniforms procured unlawfully, and then gunned people down. In other cases, perpetrators claimed to be innocent victims. Terrorists have employed similar tactics in recent years in Iraq and Egypt.

Some events were publicly reported, others suppressed. Sometimes swiftly issued reports provided very limited context; some highlighted readily available informants who ignored the role of extremists. Nevertheless, such reports often formed the backbone of public narratives, so that what was elsewhere viewed as terrorism went by different names here. (By contrast, Human Rights Watch and others have helpfully conducted fuller and longer investigations.)

The experiences of Nigerian friends regularly tore my heart out. When September 11, 2001 happened in the U.S., I thought that at last readers in the U.S. would pay attention to the massacres that had started in Jos four days earlier, beginning cycles of violence that eventually claimed thousands of lives. Yet by this point, U.S. readers naturally had other concerns. Violence continued to touch people and places I knew. In one rural community where I taught sixty local pastors, for example, hundreds of people were killed. Elsewhere, a church where I had taught was bombed. Although, because of my work, my personal sources were mostly Christian, Muslims suffered terribly also.

One difference today is that some key extremists have a name -- Boko Haram. More importantly, people recognize them as terrorists, and the current protests have drawn global attention to the problem.

The current crisis is one of the most horrendous, yet it has a larger context. The problems did not start yesterday, or even in 2002. Those who have drawn attention to this crisis should be commended. It is unfortunate, however, that it has taken such tragedy to capture more of the world's attention.