It takes a special kind of person to leave home and join a foreign militia to fight the theocratic brutes of the Islamic State's army. It takes an even more special person to realize, a little too late, that his chosen anti-ISIS militia holds a political and religious ideology that's as antithetical to his own as ISIS's.

The media's had a love affair in recent months with Americans, Brits, Aussies, and other Westerners joining Kurdish ground forces to combat ISIS. But all is not sweet in the West of Kurdistan: According to AFP's Jonathan Krohn, many of the most motivated Western fighters are Christian crusaders eager to defeat the armies of Muhammad, but they were shocked to learn they'd joined up with a bunch of Kurdish atheist commies to do it:

One seven-year US army veteran called Scott says he was planning to join the Syria-based Kurdish "Popular Protection Units" (YPG) until he found out they were "a bunch of damn Reds". Other foreigners in Dwekh Nawsha say they were turned off by what they see as the socialist streak in the YPG, an affiliate of Turkey's Kurdistan Workers' Party whose months-long battle against IS in Kobane attracted many volunteers. Alan Duncan, a prominent British foreign fighter and veteran of the Royal Irish Regiment, recently left the YPG for similar reasons. He told AFP that an exodus of foreign fighters from the YPG has begun, naming several well-known volunteers currently fighting for the group he says plan to leave in the coming days.

Indeed, the YPG is the fighting arm of the Syrian-based Kurdish Democratic Union Party, which supports the Turkish Kurdistan Workers' Party, which is labeled a terrorist group by the U.S. and until recently talked about setting up a Marxist-Leninist state in Kurdistan.

In response, Krohn writes, many of those faithful Western ISIS-hating soldiers—including a PTSD-suffering vet from Texas who "did not adjust well at peace time"—are joining a more holy-war-friendly group: "Dwekh Nawsha, a Christian militia whose name is an Assyrian-language phrase conveying self-sacrifice."

Here is some motivating imagery from Dwekh Nawsha's Facebook page:

Dwekh's Western recruits are led by an American named "Brett," 28, who's become the media's flavor du jour—having been highlighted recently by Krohn, Reuters, ABC, and the Daily Beast, among others. Here's ABC News' fawning intro:

He is 28 years old. Detroit born and bred. An Army veteran. And now he is a self-described "Soldier of Christ" back in Iraq, fighting ISIS on the front lines. "People ask me, 'Why you?' I come back and I say, 'Why not? Why just me? Where's everyone else at?" said Brett, who requested that ABC News not use his last name to protect his family back home. "Jesus says, you know, 'What you do unto the least of them, you do unto me,'" he added. "I take that very seriously." Brett returned to Iraq six months ago. In 2006-07, he served in the infamous "Triangle of Death," where he said he was badly wounded in an IED attack on his Humvee.

Other Western volunteers who've stuck it out with the socialist YPG are not so sure about the courageousness of some defectors, Krohn says:

Jordan Matson, a former US soldier who has become the poster boy of YPG foreign fighters, argued that some volunteers may have lost their bottle when confronted with the intensity of the fighting in Kobane. "Most of the Internet cowboys have come to realise this isn't a normal deployment," he told AFP. "So they lose the stomach to come or stay."

On one hand, Matson's right: YPG has seen some especially nasty action. On the other hand, his comments are indicative of a disturbing parochialism among the myriad groups fighting ISIS: Dwekh Nawsha fights primarily for the Christian Assyrians; the YPG fights for the Kurdish socialists in Turkey and Syria; the Kurdish peshmerga army is divided between Kurdish Democratic Party supporters and partisans of the Patriotic Union of Kurdistan; what's left of the Iraqi army is mostly Shiites, but they are challenged by independent Shiite militias, some Iranian-supported.

Amid this uneasy mishmash of ideologies, it's difficult to see an effective unified resistance emerging, even against a foe as universally loathed as ISIS. Even if the Islamic State's dime-store theologians and dirty executioners are dispatched, there's little to bind Turks, Syrians, Kurds, and various Iraqis together, and much to encourage new opportunists to exploit the religious and ethnic divisions between them.