In this Sunday Jan. 31, 2016 file photo, a man walks past burnt out houses following an attack by Boko Haram in Dalori village near Maiduguri.

In this Sunday Jan. 31, 2016 file photo, a man walks past burnt out houses following an attack by Boko Haram in Dalori village near Maiduguri. AP Photo/Jossy Ola

Boko Haram’s Deadly Impact

A new compilation of data gives insight into the African Islamist insurgency’s reach, tactics, and evolution. It reveals a far higher victim count than previous estimates.

Nigeria’s fight against Boko Haram remains one of the region’s deadliest conflicts despite a major military offensive to contain the African Islamist militant group and support from international partners. A new study of the conflict offers fresh perspective on how lethal it has been, especially for civilians, and the pattern behind Boko Haram’s attacks. Since 2009, the Boko Haram insurgency has killed tens of thousands and displaced millions, and violence by militants and security forces continues daily.

The study shows that though Boko Haram’s territorial control is now limited to some small villages and pockets of countryside, a shift in tactics has helped the group stay a threat to millions. It has turned to suicide bombings, which accounted for almost a third of all casualties in the first half of 2018, and has increasingly attacked Muslim places of worship. It continues to challenge government authority in Nigeria’s northeast and beyond, and it reportedly collects taxes and provides some services in areas it controls.

For its part, the Nigerian government holds thousands of alleged Boko Haram fighters, including women, children, and elderly people. The United Nations’ refugee agency estimates the conflict has displaced 2.4 million people and put more than seven million at risk of starvation. It has also led to the degradation of infrastructure, including the closing or destruction of more than half of the region’s schools, and the near-complete breakdown of an already weak public health system. While this study provides insight into the evolving tactics and targets of the group, which is now split into at least two factions, it does not show the wider harms caused by the conflict, such as disrupted communities and stunted economic development.

This new compilation of data is based on an analysis of publicly available data from CFR’s Nigeria Security Tracker (NST) and the Armed Conflict Location and Event Data Project (ACLED), an independent nongovernmental organization based at the University of Sussex. Data has been filtered to include only incidents involving Boko Haram. (Both projects also track other types of violence in Nigeria.)

Seven Years of Violence

From June 2011 through June 2018, the NST documented 2,021 incidents involving Boko Haram, in which 37,530 people were killed, nearly double the conventionally cited estimate of twenty thousand. Over the same period, ACLED identified 3,346 incidents, in which 34,261 people were killed. Both totals reflect deaths of alleged Boko Haram fighters, government forces, and civilians combined. Though ACLED tends toward lower casualty estimates and the NST higher estimates, both identify the same progression: the conflict, beginning in 2012, escalated quickly and peaked in 2014–2015. Levels of violence declined in 2016, following a major Nigerian military campaign to recover Boko Haram–occupied territory launched in late 2014 that continued through the following year. Troops from Cameroon, Chad, and Niger, as well as some mercenaries, played a major role in this campaign.

Since 2016, totals have reverted to levels seen before the 2014–2015 surge. In the first half of 2018, deaths related to the conflict appeared to be keeping pace with the previous two years.

Boko Haram’s Geographic Reach

Boko Haram–related violence has largely been confined to Nigeria’s northeast, in Adamawa, Borno and Yobe states. It has been most heavily concentrated in Borno, with the brunt of the violence borne by Maiduguri, Gwoza, and Kukawa. Violence has also become common south and east of Maiduguri, along the border with Cameroon’s Far North Region, and around Lake Chad. There have been sporadic incidents in places such as Nigeria’s Middle Belt and the capital of Abuja that have been attributed to Boko Haram.

In the country’s south and east, including major cities such as Lagos and Port Harcourt, Boko Haram–related violence is all but absent. That part of Nigeria is majority Christian and comprises many different ethnic groups but has few Kanuri. Boko Haram is reportedly largely composed of Kanuri, and many of its victims, if not most, are Kanuri as well. Notably, there is considerable anecdotal evidence that Boko Haram does not appear to be motivated by ethnic identity and has been able to recruit from other Muslim ethnic groups in northern Nigeria. The group has derived its support from a deeply impoverished population that has long felt neglected by the central government. Its followers generally adhere to a more fundamentalist strain of Islam that rejects the secular state.

This map only shows documented incidents within Nigeria that have been reported at the local government area (LGA) level. It does not include incidents in which the LGA was not reported. Government control of these borders, which were established during British and French colonial rule and do not reflect ethnic or linguistic realities, is minimal; large numbers of people regularly cross them without government administration or knowledge.

Identifying Victims of the Conflict

The NST provides a means, albeit an imperfect one, to untangle the victims of the Boko Haram conflict. ACLED does not disaggregate deaths by victim or perpetrator. Boko Haram militant deaths, totaling 18,950, account for roughly 50 percent of all deaths in the conflict. Military deaths make up 5 percent of the total.

There is credible, if anecdotal, evidence that despite claims by the military that government forces are only killing Boko Haram members, the security services have indiscriminately killed young men on the mere suspicion of being affiliated with the group. Many others have died after being detained in mass incarcerations. Spokesmen for the security forces claim that those who died in prisons were all Boko Haram fighters, but in almost all cases there was no judicial process to make such a determination.

According to the two data sets, civilians have borne roughly 45 percent of conflict-related deaths. ACLED attributed 15,107 deaths to violence against civilians. The NST documented 15,953 civilian deaths, attributed to both military and Boko Haram attacks. The vast majority of these were the result of attacks by Boko Haram.

Both data sets found 2014 and 2015 to be the worst years for civilian deaths. However, the NST finds that 2014 was dramatically worse for civilians, on par with 2015. This is partly explained by ACLED’s decision to use lower estimates of deaths.

Shifting Tactics

There is a long history of popular insurrections against government authority in West Africa, particularly in Nigeria. However, suicide bombings as a political weapon were almost entirely absent before 2011. Boko Haram has since adopted suicide attacks as an important tactic in its struggle against government authority.

After relatively low levels of suicide attacks through 2014, the number jumped in 2015 to 114 attacks, or just over two suicide bombings a week. In the first half of 2018, there were thirty suicide bombings in northeast Nigeria, killing 297 people, signaling that such attacks have continued with some regularity. Boko Haram’s use of suicide bombers perhaps copies a tactic used by Islamist jihadis in the Middle East and elsewhere. Its reliance on this tactic reflects the overall decline in its direct confrontation with the army and security services, after Nigerian forces drove Boko Haram out of much of its territory, and its current strategy of attacking soft targets. One faction appears to still be focused on military targets.

Suicide attacks have also accounted for an increasing proportion of deaths. This approach may have become more attractive to Boko Haram leadership because of its ability to terrorize local populations and undermine confidence in the ability of the government to provide protection, though the reasons behind the rise in suicide bombings remain unclear.

Boko Haram frequently attacks churches and mosques. Through 2014, Boko Haram targeted churches more often than mosques. In its messaging and public statements, the group has closely linked Christianity with the West, Nigeria’s secular government, and ethnic groups from other parts of Nigeria that are often perceived as rivals for local influence.

In recent years, the group has attacked more mosques than churches. It is unclear why, but it is possible that power struggles between different Boko Haram factions are playing a role. Also possible is that the shift is punishment for popular support for then President-elect Muhammadu Buhari and reflects Boko Haram’s public opposition to democracy. Attacks on churches notwithstanding, Muslims have borne the brunt of violence since the conflict began.

Looking Ahead

Over the past seven years, Boko Haram has demonstrated flexibility and remains a formidable threat to the Nigerian state despite losing much of its territory. Though the group is undoubtedly less powerful than it was in 2015, there is no sign that the government will defeat it in the foreseeable future. In the meantime, the pervasive threat of violence sharply curtails the ability of international aid organizations and donor countries to provide humanitarian relief. Though this study traces how the group has evolved in recent years, there remain many unanswered questions about Boko Haram’s staying power. Chief among these is the extent of the group’s popular support and the extent to which the security services are fueling Boko Haram recruitment.


ACLED and the NST provide quantitative tracking of the conflict in northeastern Nigeria. Both projects rely entirely on open-source, published materials, typically from the Nigerian and international press and reporting from human rights groups and other international organizations. Go here for more information on ACLED and herefor more on the NST.

ACLED and NST data should be viewed as indicative rather than definitive. They likely understate the scale of the conflict because journalists and human rights organizations face challenges monitoring the large number of inaccessible areas where violence takes place. Furthermore, public accounts of the same incidents frequently vary. Media often rely on official sources, which have an incentive to understate the number of civilians killed and overstate the number of Boko Haram militants killed. Coding those discrepancies requires judgement calls on the part of researchers. Nevertheless, tracking public reports of politically related violence provides the best, if imperfect, indication of the size, extent, and trajectory of the conflict.

Python and Jupyter Notebook were used to clean and prepare the data. Visualizations were built in Tableau Public and redesigned in Adobe Illustrator. You can download the datasets here.

This piece, first published by the Council on Foreign Relations, is used with permission.