In a year packed with terrorist attacks, the world's deadliest militant group has carried out massacres the size of the San Bernardino killings once or twice a week. And over time, it has undertaken dozens of attacks that dwarf November's deadly rampage in Paris, sometimes shooting down several hundred civilians at a time.

Boko Haram, the northeastern Nigerian Islamist group, has been even more deadly than Islamic State. And each time Nigeria’s army seems to have made substantial inroads toward wiping it out, the group has quietly rebuilt. Its members cut the throats of schoolboys, casting them aside to bleed to death in the sandy dust. And they behead victims, like Islamic State, videotaping the atrocities.

Although Boko Haram has at times issued threats to the West, it has largely focused on poor Nigerian villagers, far from the media spotlight.

Five years ago, in a clandestine interview at a small, deserted zoo in Kano, a leader of Boko Haram spoke in a quiet, lecturing tone, never making eye contact. The Islamist fighter appeared cold and emotionless, even when describing acts of terrorism against the U.S. as “divine worship.”

“They are fighting Islam, and we will also fight them, if we get the chance,” he said.

I was garbed in a heavy Islamic outfit and had walked around for 10 minutes with a go-between, waiting for him to show up. Three men followed us for several minutes before a signal was given and we were told to sit on a bench to talk.

Boko Haram, originally modeled on Afghanistan’s Taliban, was at its lowest ebb in 2010, with Nigerian authorities confident they had brought the organisation to its knees after having killed 700 of its fighters in a battle the previous year. But Boko Haram went underground, regrouped and has since launched thousands of attacks. Last year, it was the world's most deadly terrorist group, according to the Global Terrorism Index released recently by the Institute for Economics and Peace, a think tank.

“It’s proven to be one of the most resilient organisations. It’s evolved quickly. It’s shifted alliances. It’s been pronounced dead numerous times,” said J. Peter Pham, director of the Africa Center at the Atlantic Council think tank.

“At one point it had no outside support. Then they got support from al-Qaida. It dropped al-Qaida and went over to the new winning team, ISIS,” he said, referring to the militant group Islamic State, which claimed responsibility for the recent terrorist attacks in Paris.

Boko Haram was blamed for recent twin suicide bombings in Kano: one carried out by an 11-year-old girl, and a market bombing in Yola that killed 34. The extremist group was responsible for 6,644 deaths in 2014, a 300 percent increase from the previous year, according to the Global Terrorism Index. In comparison, Islamic State killed 6,073.

The overall number of terrorism deaths increased to 32,685 in 2014 from 18,111 in 2013, the report says; the most terrifying place to live was in the northeastern Nigerian region that makes up Boko Haram's home turf.

The Paris attacks on Nov. 13 attracted more social media and mainstream media attention than deadly Boko Haram raids on towns and villages with names like Gamboru Ngala, Gwoza, Bama and Dikwa. Attacks in Nigeria have such a low media profile that even activists who condemned Facebook users for focusing on the Paris massacre but not on another the day before in Beirut — for which Islamic State also claimed responsibility — forgot to mention Nigeria’s ongoing strife.

On that day in 2010 at the Kano zoo, I had my notebook out, scribbling away. On the same bench, a severe, formal 30-year-old man with a beard and a bottle-green flowing garment expounded on Islamic texts.

The most curious part of the interview was the absence of any possibility for meaningful connection.

When I glanced at the face of the man, identified as Musa, it was impassive and distant. He couldn’t help betraying his distaste for the interviewer, clearly annoyed when I began by asking questions. I was brusquely silenced. Instead, a long religious speech was in order, much of it impossible for me to comprehend.

Musa, who declined to give his surname, was so cold and uncompromising about the group's extremist ambitions to establish an Islamic state in Nigeria, a nation of 170 million divided between Christians and Muslims, that it was difficult to imagine any possibility of compromise.

Victims of the group, and of others like Somalia’s Shabab, describe attackers displaying that same sort of cold, emotionless aura in some of the continent's worst terrorist attacks, including two in Kenya: the Westgate shopping mall massacre in 2013, in which 67 people were killed; and another at Garissa University College in April, in which 148 were slain, most of them students. Both demonstrated how much damage a few heavily armed suicidal men can wreak in a short length of time.

As in Paris and San Bernardino, typical Boko Haram attacks target people simply going about their business.

Dozens of terrorist fighters swarm into a village or town on motorcycles or in pickup trucks and open fire on the market or square. In many attacks, hundreds of people have been killed, some of them burned alive, according to survivors. Men and boys as young as 10 would be dragged from their houses and shot, or slaughtered with knives.

Hauwa Umar saw men’s beheaded bodies strewn about the town of Gwoza after Boko Haram attacked in August last year.

“There were uncountable bodies without heads,” she said in a March interview. “Boko Haram kept saying, ‘Stop crying! Stop crying!’ I couldn’t stop crying, and they'd shoot their guns in the air to shock you. But I kept on crying.”

Women and children were abducted as sex slaves. (Hundreds have been released in recent months, but not 219 girls still missing from among 276 abducted from Chibok last year, triggering the Twitter hashtag “Bring Back Our Girls.” At the time, Boko Haram rocketed to global attention, before quickly fading.)

Shehu Sani, a Nigerian senator and human rights activist, has been involved in repeated efforts to negotiate a cease-fire with Boko Haram under former President Goodluck Jonathan and his successor, Muhammadu Buhari. But the talks, also designed to secure the freedom of the kidnapped Chibok girls, have yet to succeed. Buhari set a deadline to crush the militant group by December, but his office recently acknowledged the effort would take longer.

Boko Haram has become more violent and more difficult to negotiate with since rebranding itself as Islamic State’s West Africa Province this year, according to Sani.

“They have stepped up attacks on soft targets, killing innocent people,” he said, adding that the army's success in driving Boko Haram from its forest hideouts in recent months merely resulted in the group going underground, moving to cities and launching attacks on civilians.

In 2010, Musa called the massive defeat of 2009 a “blessing.”

“Now that we’ve dispersed we can conduct our activities without any monitoring or any surveillance,” he said.

Early on, the group acted like a religious cult, demanding that followers sell all of their “sinful” belongings including vehicles, furniture, televisions and even the tools of their trade to fill its coffers. Wives described husbands who refused to allow them to leave the house. The men grew long beards and came home with guns and bombs, the women said.

Later the group won funding and support from al-Qaida’s African affiliate and early this year switched loyalties to Islamic State, embracing its apocalyptic ideology in return for its backing.

“With that type of ideological absolutism where they’re aspiring to be a universal empire of religion, there’s no compromise possible,” said Pham, the analyst, referring to Islamic State. “And Boko Haram is evolving the same ideology. Perhaps earlier in its history, when (it) was primarily a local concern and its ideology was not as rigid in its adherence to absolutism, perhaps there might have been a possibility of compromise. But that moment has gone by.

“To date, they have not shown themselves to be a direct threat to Western countries,” he continued. “But I wouldn’t rule it out in the future. It has evolved very quickly. That they haven’t attacked foreign targets doesn’t mean they don’t have that ambition or couldn't evolve a strategy.”

•Photo shows scene of a Boko Haram attack.

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