As part of its latest immersive documentary on Westerners fighting the Islamic State on the front lines in Syria, Fusion’s Naked Truth team trekked downrange to find out how these volunteers did it. What we found was a minefield of hazards and challenges — and that’s before you even get on a plane to the war zone. Read below to learn the steps involved… and watch the video above for a primer on the U.S.’s ostensible allies in the fight against ISIS.

Vytenis Didziulis

1. Know who you’re going to be working for. Fighting ISIS as an unaffiliated Westerner usually means embedding with the Syrian Kurdish militia known as the People’s Protection Units, or YPG.

The YPG actively pursues Western volunteers and is considered the United States’ most effective ally in Syria in the war against the Islamic State. (Watch the video above to understand why.) Hundreds of American and European volunteers have fought in Syria with the YPG since the Islamic State’s brutal offensive in 2014.

But volunteering with the YPG is a delicate and dangerous proposition. At least 10 foreign volunteers have been killed fighting ISIS, and the terror group has reportedly put out a $150,000 bounty for the capture or killing of western YPG fighters.

Additionally, volunteers may face arrest and prosecution upon returning home. The YPG is closely linked to the PKK, or Kurdistan Workers’ Party, which is designated a terrorist organization by the United States and Europe for its role in a bloody guerrilla war in Turkey that has killed 40,000 people.

Vytenis Didziulis

2. Make contact. The most common way to join the YPG is through their official foreign recruitment arm, a Facebook page for a group called Lions of Rojava.

Getting in touch with them can be complicated. The site is inundated by requests to join, and messages via Facebook messenger are rarely answered. Many would-be recruits complain of never hearing back or being put on hold for months.

Vytenis Didziulis

3. Don’t be (too) crazy. Those who are prioritized are required to answer an online questionnaire, asking about their motives for joining, their political and religious views, and their basic knowledge of the Syrian conflict and the YPG’s ideology.

The recruiters are basically looking to weed out racists, homicidal maniacs, and felons. The Lions of Rojava has attracted scores of volunteers who see the group as the modern-day version of the International Brigades who fought in the Spanish Civil War. The conflict draws its share of Ernest Hemingway types. Or at least Hunter S. Thompson types.

But it has also attracted glory seekers looking for a story to tell at a bar; felons on the run; and even out-of-work Hollywood actors.

“We don’t want people to come here only to kill,” says Deniz Sipan, commander of the YPG’s foreign volunteer training program who adds that some Westerners are hell-bent on killing Muslims. “We have this kind of people, which is weird, because most of the Kurdish people here are Muslims,” she says. “But according to those people, everyone with any kind of relation with Islam must be killed. So it’s dangerous on us.”

Vytenis Didziulis

4. Take a risky plunge. If you are able to pass the online filters, you’ve done the easy part. And if you really want to join, you’ll have to commit a real leap of faith.

Your contact will be a faceless entity on the other side of an encrypted messaging service who will instruct you to buy a plane ticket to the Kurdistan Regional Government of Iraq. You’ll be given a phone number and told to call it as soon as you pass through customs. The person on the other end of the phone will give you an address to a YPG safe house. Some recruits I spoke to said they were wary of walking into an ISIS trap.

“The part where I didn’t feel safe was when I landed at the airport,” says Hanna Bohman, a Canadian volunteer. “I was taken to the safe house, and that was a time, though, that if it was gonna go wrong, that’s where it would go wrong, right there. So that was a bit stressful.”

Vytenis Didziulis

5. Make a run for the border. The YPG will then smuggle you into Syria from Iraq. Most of the country’s borders are closed, and Iraq’s Kurdish regional government has detained foreigners going to or coming back from Syria.

The closed border means you’re crossing illegally, probably in the dead of night, across a small river, and then walking eight hours or more.

Vytenis Didziulis

6. Learn what you’re really doing there. The first stop inside Syria will be the foreign volunteer training center, where new recruits get an orientation in YPG ideology and basic military training.

When I was there in late 2015, I met only one former soldier, from Sweden. The rest were Western European socialist college kids, mostly social sciences buffs, and a son of Arab refugees who looked several years shy of 18.

Related This woman risked her life to rescue fellow Syrians from the rubble

Like the PKK, the YPG has its ideological roots in Marxist-Leninism; some Western volunteers, seeking a Christian holy war against ISIS, have been shocked to find that they were being enlisted to fight for a socialist cause.

The YPG also maintains a cult of personality around their leader, Abdullah Öcalan, or Apo. If you go to Rojava, his face is the one you’ll see in posters in every government office. He’s pretty ubiquitous.

The YPG’s political wing, the Democratic Union Party, has declared the areas of northern Syria under YPG control a federal autonomous region.

Vytenis Didziulis

7. Have some nationbuilding skills. (HINT: You probably already do.) The Kurds are used to being the underdogs in the fight, but going from oppressed and stateless people to rulers of territory presents a host of new challenges. New college-educated recruits are mainly here to help with that transition — not to find glory on a battlefield.

“Those Westerners who come here, they’re not just here to fight,” says Sipan. “We don’t need soldiers, actually. We have too many soldiers already. We need people who represent their countries. So when you’re from Australia, or you’re from Canada, or you’re from America, or you’re from Sweden, it’s not only you here, it’s your whole country helping us and supporting us.”

Vytenis Didziulis

8. Keep your eyes open. Every party in an armed conflict has an agenda — and the Kurds, historically stateless people with populations in Iraq, Iran, Syria, and Turkey — are no exception. As Sipan’s quotes show, Kurdish factions desire statehood and Western recognition, even when they disagree among each other. Whether you’re a soldier or a rear-echelon technician, you’re doing the YPG’s bidding, not Uncle Sam’s.

And there’s some evidence that the YPG’s bidding has violated norms of human rights in its civil-war campaign. Amnesty International and Human Rights Watch have alleged that authorities in YPG-held territory displaced Arab and Turkmen residents, razed their villages, detained people without cause, and were slow to tackle killings and disappearances on their watch.

At the same time, watchdogs have praised the Kurds for establishing security and being somewhat transparent — allowing access for monitors to prisons, for example, and vowing to stop recruiting underage soldiers. Even so, there’s plenty for new recruits to be wary about. Know whose bidding you’re doing… and be open to alternatives. There are plenty of other ways to aid ISIS’s victims in the West, too.

Want to learn more? Watch “ISIS Fighters,” Fusion’s hourlong documentary on the frontlines in the battle against the Islamic State, below.