This week, President Trump threatened to send the U.S. military into Nigeria and to cut off American aid for not doing enough to protect Nigerian Christians.

Nigeria and its 236 million people comprise the most populous nation in Africa, roughly split between Christians and Muslims.

For years, it struggled to curtail violence across the country,

from international terrorist groups to disputes between farmers and herders. But now, as Nick Schiffrin

reports, its leadership must face threats from both its internal adversaries and from the White

House. In Nigeria's northeast, the carcass of a truck is still smoking.

An office building's facade is burned black.

And an army pickup charred beyond recognition.

All targets of Islamic State, West Africa Province, which two weeks ago filmed as it torched

a military barracks and launched simultaneous attacks across four districts.

For years, Islamist terrorists have plagued northern Nigeria.

Best known as Boko Haram, they haven't only targeted the military.

Boko Haram violently opposes female education, and in 2014, kidnapped

276 schoolgirls, 82, remain in captivity. It's bombed mosques, blowing up this place of prayer

in 2014, killing 120. Boko Haram is also targeted Christians, as I saw in 2015 in the eastern city of Mubi.

Outside the nearby Church of the Brethren, the damage is everywhere.

Inside, high above the podium, the fire set by Boko Haram almost erased the cross from the wall.

Sixteen parishioners died.

Ilya Usman is the church's secretary.

When these people landed in Mubi, they will ask you, are you a Christian or a Muslim?

When you say you're a Christian, they will shoot you.

There's no one single church left in Mubi. They are burnt it.

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