The young man spoke nonchalantly and occasionally flashed a serene smile as he spoke into the camera, belying the message his video would deliver to the world: That he was responsible for an August 2011 suicide attack against the United Nations headquarters in Nigeria's capital of Abuja.

When the footage surfaced the following month, the world had barely heard of the Islamist extremist group that has come to be known as Boko Haram, but the explosion that ripped through the UN building, killing 23 people and injuring 116, would begin to change that. The slight young man in the video illustrated the growing problem of radicalization within the country — he was identified as a 27-year-old auto repair worker, a seemingly ordinary resident of northeastern Nigeria.

Countless more attacks and many thousands of deaths later, the conflict with Boko Haram has arrived at a crucial moment with a mixture of sorrow and cautious optimism. It presents an opportunity to address the root causes of the insurgency and begin to remedy them.

As Nigeria marks a year since the kidnapping of 276 girls from their school in Chibok — another atrocity that would draw global attention to the insurgency's extreme brutality — hope of finding the 219 students who are still missing has faded. Hundreds of thousands of people have been displaced by a violent upheaval wrought by the extremists and the military's response to their relentless campaign, with soldiers themselves accused of horrifying abuses.

But recent weeks have also brought evidence of profound change within Africa's most populous nation. On March 28, Nigerians replaced an incumbent president in a democratic election for the first time ever — a truly historic achievement in a country with all-pervasive corruption and a history of rigged polls.

Muhammadu Buhari, president-elect of Nigeria. (Photo via Flickr)

The man who will now lead Nigeria through this period of deep turmoil is Muhammadu Buhari, who previously governed the nation for nearly two years after taking power in a 1983 military coup. That period was known for his ill-conceived "War Against Indiscipline," a draconian attempt to coercively reform the country through police state tactics. He has since pronounced himself a committed democrat who has abandoned his old authoritarian ways, and Nigerians will be watching closely to see if he lives up to that promise.

There is reason to believe that Buhari, a retired Muslim general from northern Nigeria, will be in a better position to subdue the insurgency than his predecessor Goodluck Jonathan, a southern Christian who often seemed indifferent to Boko Haram's campaign until it was clearly out of control.

Buhari has said that he will pursue the insurgents militarily. An offensive involving neighboring countries over the past couple months has made important progress in removing them from towns they had occupied in Nigeria's northeast. It has also helped to make clear that armed force will not be enough.

Buhari's electoral victory might have assuaged the feeling of hopelessness in the northeast in some small way, but only real progress in rectifying the underlying issues will have a lasting impact.

The regional effort has revealed the shortcomings of Nigeria's army, with the oil-rich country needing the help of its smaller and poorer neighbors to effectively battle Boko Haram. Its decline is symbolic of the astonishing levels of graft and disastrous mismanagement that have robbed Nigerians of any trust they might have once had in their institutions. Millions of people have remained impoverished as corrupt politicians pocket oil money and shop for luxury cars and private jets.

Northeastern Nigeria, where Boko Haram emerged, has been hit especially hard by unemployment and poverty, and trails much of the rest of the country in education. In Borno state, the center of the insurgency, a report presented to UNESCO estimated the literacy rate at 14.5 percent compared to 92 percent in Lagos, Nigeria's economic powerhouse in the southwest.

Countering Western education is, of course, part of Boko Haram's mission. This helps explain why the group targeted the students at Chibok and other schools. "Western education is forbidden," the group's founder Mohammed Yusuf told authorities after he was caught in 2009. "Any type of knowledge that contradicts Islam, Allah does not allow you to acquire it."

Other areas of northern Nigeria, which is predominately Muslim, endure economic and political marginalization similar to that seen in Borno. The country's mainly Christian south has had its share of troubles as well — including a violent militancy in the oil-producing Niger Delta region — but it has fared better, particularly because it is where the oil industry is based.

Boko Haram leader Abubakar Shekau. (Screengrab via YouTube)

Islamist extremism thrives on destitution, ignorance, and disillusionment, and it developed in northern Nigeria for these reasons, well before Boko Haram. In the 1970s, a movement sprouted under the leadership of a radical preacher known as Maitatsine who interpreted the Qur'an in unorthodox ways and was said to have insisted on the absolute rejection of Western civilization. He and his followers viewed the secular Nigerian government as illegitimate, sparking deadly riots in 1980 in Kano, northern Nigeria's largest city. It was a portent of what would follow.

Years later, with Nigeria's justice system plagued by the same corruption that had degraded other institutions, northern Islamic reformers pushed for the use of Sharia law in criminal cases. Opportunistic politicians took up their cause around the time the country returned to civilian rule in 1999, and Sharia became official policy across most of the north, though it is selectively applied.

Boko Haram began to take shape shortly afterward, with a profound sense of hopelessness in the northeast swelling its ranks and leading to a 2009 uprising that left around 800 people dead. Nigeria's security forces captured and executed Mohammed Yusuf. His bloodthirsty deputy, Abubakar Shekau, then took over, and the group gradually evolved into a monstrous slaughtering machine, willing to engage in staggering levels of butchery.

It recently pledged allegiance to the Islamic State group, a development that has received much attention and which should be monitored closely. But true links between the two groups remain questionable, and many in Nigeria regard the pledge as a propaganda stunt. Above all, it should not distract from the socioeconomic factors behind the insurgency and the Nigerian government's inability to stop it.

The young man in the video is who Buhari must keep in mind when he assumes the presidency on May 29. His electoral victory might have assuaged the feeling of hopelessness in the northeast in some small way, but only real progress in rectifying the underlying issues will have a lasting impact.

An immediate effort to cut back on corruption and restore the army must be one of Buhari's first orders of business, but he should also lay out a clear and substantial plan to improve and protect education and infrastructure — and then be sure to follow through. Nigeria has seen its leaders promise many detailed projects, from finally providing steady electricity to building good roads, but a failure to deliver them has only compounded public disillusionment.

Proof of progress would demonstrate for Nigerians that their commitment to democracy in the recent election was not in vain. And it would give the nation's disenfranchised citizens reasons to live so that they are no longer as willing to die.