Chad Martin, a ruddy-faced 22-year-old American, is driving a pickup truck through the rubble-strewn streets of Sinjar, Iraq. Riding shotgun next to him is Eric Detweiler, also 22, from Colon, Michigan.

But they aren't soldiers, or private military contractors, or even civilians who have come to war-ravaged northern Iraq to take part in the fight against Islamic State, as dozens of others have done. They are devout Christians from a Protestant sect known more for shying away from the world than for going out to war zones — but they aren't in Iraq to proselytize in a largely Muslim land, they say.

They are volunteers — and the reason they are here becomes clear when looking at the truck's bed, where Delvin Zimmerman, a 26-year-old from the same church as Martin in Lancaster, Pennsylvania, clutches a large pane of glass. They have come to help rebuild a town destroyed by war.

More than six months after Sinjar was retaken from Islamic State militants, a small group of North American Mennonite volunteers is the only permanent humanitarian presence in this ghost town at the foot of Mount Sinjar.

Sinjar used to be an agricultural hub, whose 50,000 inhabitants included Yezidis, Kurds, and Arabs.

In summer 2014, it became synonymous with the mass atrocities committed by Islamic State extremists as they swept through northern Iraq. The IS militants displaced an estimated 90 percent of Iraq's Yezidi religious minority, killing thousands and enslaving many more of their women and children. Those from Sinjar who could escape fled to the mountain above the town. In response, a US-led coalition began a campaign of airstrikes that inaugurated the West's war against the Islamic State, and helped Kurdish and Yezidi militias retake the city last November.

But the cost of Sinjar's liberation was its near-total destruction, and since then little has been done to rebuild. Local militias have cleared an estimated 40 tons of improvised explosive devices left behind by the retreating jihadists, but with an estimated 85 percent of homes destroyed or damaged, and with no functioning services, only a handful of civilians have returned.

The Mennonite volunteers are hoping to encourage more families to come back by cleaning up looted homes, fixing broken windows, and installing doors. Returning Yezidis say they are grateful for any help, but with no one in Iraq or overseas volunteering to pay the billion-dollar repair bill for the city's infrastructure, local officials now question whether Sinjar is beyond saving.

Eric Detweiler installs a pane of glass in Sinjar. (Photo by Campbell MacDiarmid/VICE News)

Martin stops the truck in front of an old house occupied by fighters from the Kurdistan Worker's Party, or PKK. Inside they quickly install the glass in the window of a high-ceilinged room furnished with just a ping-pong table. Their job done, they shake hands with the fighters, who thank them for the new windows.

"We really appreciate the support of our foreign friends who have come here to rebuild Sinjar," Heval Mohamed, a stern-faced guerrilla, says. "We accept any help from any side."

The Mennonites have no allegiance to any side in this fight. They're doing this to help civilians, they say. "We'll fix the glass for a military group if the house is going to go back to a family afterwards," says Martin.

The PKK is listed as a terrorist organization by the US government, for its bloody 30-year insurrection against the Turkish government. But its armed wing was also the first to come to the aid of the beleaguered Yezidis after the peshmerga militia from another Kurdish faction retreated from Sinjar in August 2014. The PKK is now losing influence to the Kurdistan Democratic Party, or KDP, the dominant party in Iraq's autonomous Kurdish region.

The Yezidis for their part are deeply distrustful of both the Kurds and of their former Arab neighbors, many of whom participated in the slaughter of an estimated 1,000 Yezidis just in Sinjar town alone. Many Yezidis now oppose the return of any Arabs or even Kurds to the town.

The Mennonites navigate this complex landscape of rubble and rivalries with a single-minded focus on their stated mission. "We do windows and doors," says Martin, waiting for dinner back at the house they have refurbished in the town. "I figured it's something we can start at. We're a small organization with limited donations."

Plain Compassion Crisis Response was formed in September 2014 by members of the Mennonite communities of Lancaster and Franklin counties, horrified by television reports showing the plight of the Yezidis. "We got people together and said, 'Let's go,'" Martin says. "It got formed kinda out of chaos and we've been trying to organize the chaos ever since."

The first members of the group bought plane tickets to northern Iraq and landed in October 2014 without knowing exactly what they would find or what assistance they could give. But service is a core value of the Mennonites, Martin says, and they were determined to help.

Martin arrived in January 2015, and worked in Duhok province helping to improve the accommodation of displaced Iraqis, many of whom live in unfinished homes. After the earthquake in Nepal last year he flew there to provide aid, but when Sinjar was freed last November he was drawn back. Winning over local officials with his plan to help rebuild, he was offered a house to move into. "I thought, OK, we'll move in, and worry about everything else later," he recalls.

None of the volunteers had experienced conflict zones before coming to Iraq, although a few of them underwent five days of emergency response training that included being shot by paintball guns. "A lot of people in our church are more involved with local issues, they're not as big on going into war zones," Martin says. "I'm a little bit of an oddball when it comes to that."

One of the original Anabaptist sects to emerge from the Protestant reformation, the Mennonites are similar to the Amish — who are famous for riding horse-drawn buggies and avoiding modern conveniences — but less bound by rigid rules. Most live in agricultural communities, where hard work and service to others are predominant values. They aren't the sort of Western aid worker often seen in war zones. Their church, in fact, preaches non-violence.

"I wouldn't necessarily say we're pacifists," says Joshua Kurtz, a 23-year-old son of a preacher from Snowhill, Maryland. "That sounds as if we're passive. But we're definitely against war."

While the volunteers all cite seeing the horrors of ISIS on television as motivation for wanting to help, none seem particularly worried by the thought that the fighters remain just kilometers away and would surely relish the opportunity to harm or capture American Christians.

"It's just awesome," says 20-year-old Marylander Jennel Kauffman, "being in a war zone. The best part is seeing people get home again."

One of two women in the group, she works alongside the men, but she and 26-year-old Virginian Elizabeth Yoder also rise early to bake cookies and prepare breakfasts of biscuits and gravy.

Yoder is also nonchalant about the risks of living in the shadow of IS. She grew up speaking the German dialect known as Pennsylvania Dutch in an Amish community before joining a Mennonite Church, and living in the rubble of a Middle Eastern war is as far from home as it gets. But she says she's adjusted well: "Growing up in an Amish house probably makes it easier for me to live here without modern conveniences."

Watch VICE News' Reclaiming Sinjar: Pushing Back the Islamic State:

While Martin heads a small core of semi-permanent staff in the town, including Yoder and Kauffman, Kurtz is part of a group of five on a two-week rotation working in Iraq as part of a seven-month Christian adventure gap year. It's a period dedicated to learning about personal development, leadership, and spreading the word of Jesus Christ.

But in Iraq, where Islam is predominant and proselytizing on behalf of another religion can get people in serious trouble, they're not preaching. "The only thing we can do is be a living example of what God has done in our lives," says Martin. "We've chosen to show Christ's love by helping them fix what's been broken."

So far, Martin says, they've fixed up 170 of 473 houses that they've been asked to work on, in addition to a school. "They're good kids," says Naim Sinjari, who runs a business supplying doors to the volunteers.

They've also set up Yezidi cousins Khalie Murad and Zedow Ali in business running a glass shop. The cousins bring the glass in from the nearby city of Duhok and sell it to the volunteers, who receive funds raised from their churches back home. "We're planning to keep running the glass shop when they leave," says Murad.

Jenell Kauffman, 20, clears debris and household belongings from a burned-out Sinjar house. (Photo by Campbell MacDiarmid/VICE News)

Martin says they've maintained good relations with the local authorities too. "We're one of the few organizations in the city where we can walk into the offices of [local political parties the] KDP, PUK and the PKK, and they like us."

Many Iraqi Kurds are fiercely loyal to a single party, and the two dominant parties, the KDP and the Patriotic Union of Kurdistan or PUK, even fought a civil war during the 1990s.

One group they have yet to win over is the local KDP Peshmerga leadership. "They think we're spies," says Martin. "They think, 'Why would someone come all the way from America and volunteer here?' When you think about it from their perspective it doesn't make sense."

But local policeman Asif Haji says he understands what they are doing. "They've come as humanitarians to help people. It's a good job that they're doing," he says, sitting outside his house and smoking a water pipe. "Suoro fixed my windows," he adds, calling Martin by the Kurdish nickname, Red, his sunburn has earned him.

Haji has bigger problems than broken windows and looted doors, though. "It's a lousy situation in the city today," he says. "There's no water, no proper electricity, and a shortage of food."

There are also rumors that IS will counterattack. "I've sent my family back to live on the mountain above the town," Haji says. "I'll wait until the situation is safe before I bring them back."

The local head of security in Sinjar also agrees that the town is still too dangerous for civilians. In a heavily defended house, requisitioned by his fighters, Major Qassem Simo, who heads the KDP's Asayish security in Sinjar, says, "the main challenge for us is civilians wanting to return. We try and explain to them that we prefer if they don't return because it is not safe yet."

There is still the danger of ISIS booby traps and indirect fire. Shelling hit the town in early May. "ISIS is only five miles from the city, in some places closer," Simo says. "The peshmerga have cleared 90 percent of the town but there could still be booby traps under the rubble."

The Mennonite volunteers are undeterred by the danger. "You hear 'em coming in, hear 'em whistling," Martin says of the shelling. "But as long as it don't get too loud, it ain't too close."

He is similarly dismissive of the lingering danger of booby traps and unexploded munitions: "We hardly find IEDs any more. They cleared 'em up real good," he says of the Improvised Explosive Devices that IS left behind by the ton.

The Mennonite volunteers working in Sinjar start their day with calisthenics. (Photo by Campbell MacDiarmid/VICE News)

But local nurse Kalash Edo questions whether their efforts might be better applied elsewhere. The 23-year-old gives medical training to Yezidi militiamen stationed around Sinjar, but now lives in the less damaged town of Snuni to the north of Sinjar mountain. "Thousands of people are moving back to Snuni, why don't they work there?" he asks. "No one wants to move back to Sinjar under the attacks and the rockets, they want to leave it as a memorial."

Even the mayor acknowledges that the town may never be rebuilt. "As the administration, we believe that it would be a good idea to build a new Sinjar elsewhere," says Mahama Khalil Qassem, from his office in the ruined town. "This would be better economically, security-wise, and in terms of people's psychological well-being."

Qassem estimates that the cost of rebuilding could be up to $10 billion and says so far neither the Iraqi central authorities in Baghdad nor the Kurdistan Regional Government have offered up the money. Both administrations are facing budget crises brought on by falling oil prices and the ongoing cost of war, and with other destroyed cities vying for reconstruction funds, Sinjar is not top priority.

The Mennonite volunteers say they'll keep working, regardless. The day after fixing up the PKK base, the whole team was busy sweeping out a burned-out house, filling wheelbarrows with charred home furnishings, and clearing the broken glass from window frames.

"The only complaint people who live here have," Martin says, "is that we don't get there fast enough sometimes."