MELISSA BLOCK, HOST:
This is ALL THINGS CONSIDERED from NPR News. I'm Melissa Block.
AUDIE CORNISH, HOST:
And I'm Audie Cornish. Syria's bloody civil war is not just being fought by Syrians. Thousands of foreign fighters have poured into the country, too. Many are Sunni militants waging war against government. That includes Islamist extremists and al-Qaida-linked militias.
There are also those who support the regime of Bashar al-Assad: Shiite extremists from Lebanon, Iran and increasingly from Iraq are joining the fight. NPR's Deborah Amos has our report from Beirut.
UNIDENTIFIED MAN #1: (Speaking foreign language)
DEBORAH AMOS, BYLINE: This video is part of a recruitment drive aimed at Iraqi Shiites. The video combines powerful symbols: a sacred Shiite shrine, Sayyidah Zaynab near Damascus, a place of pilgrimage for Shiite Muslims for generations. The defenders: Shiite militias armed to protect the shrine and their faith. In Iraq, the message is reinforced in the mosques. Shiite Islam is under threat from Sunni extremists. Iraq's Shia are obliged to fight.
PHILLIP SMYTH: This is a holy war. You have to go here. If you don't do so, you're disobeying God. This is how they've presented it.
AMOS: That's Phillip Smyth, a researcher at the University of Maryland. He says militants from Iraq began to cross the border last year. Now, he says, there are thousands of Iraqi fighters in Syria.
SMYTH: There's been increased attempts to recruit in Iraq. I mean, there are billboards up in Najaf and Karbala that are trying to recruit people.
AMOS: These are Shiite holy cities where each recruit gets $500 a month, he says, and free military training.
SMYTH: There are training programs that are in Lebanon. There are also programs in Iran, and the programs in Iran are far more extensive for the Iraqi Shia.
AMOS: This didn't start out as a sectarian war. The Syrian revolt began as an uprising against the government. But the majority of Syrians are Sunni Muslims while top officers in the Syrian army, top officials in the government, including President Bashar al-Assad, are Alawites, an offshoot of Shiite Islam. What began as a rebellion has deliberately been transformed by both sides into a sectarian battle.
The latest wave of combatants are Iraqi Shiites, says activist Abu Qatada(ph), who has seen them on the front lines. He spoke via Skype from Gutah(ph), a besieged suburb near Damascus.
ABU QATADA: (Speaking foreign language)
AMOS: Each Iraqi brigade has its own flag and distinctive slogan, he says. We also recognize them by their accents. He rarely see Syrian soldiers anymore, he says. In his town, rebels mainly face Iraqis and Lebanese Shiite fighters from Hezbollah. And Phillip Smyth says Iraqi units are now fighting across Syria.
SMYTH: These Shia Islamist forces, which are being used in Syria, are generally all over the country. In a number of these key battle fronts, if they weren't there, Assad would not be able to launch a number of main offensives.
AMOS: The latest offensive is near the Lebanese border, where a video emerged of three Iraqi fighters captured, then interviewed, by Hadi Abdullah(ph), a Syrian activist.
UNIDENTIFIED MAN #2: (Speaking foreign language)
AMOS: The Iraqis say they are part of an organized militia, paid to fight, trained in Iran. But when the activist accuses the men of coming to Syria to kill Syrians, one of them starts to cry.
UNIDENTIFIED MAN #3: (Speaking foreign language)
AMOS: Now you cry and regret it, says the activist. The families of those you killed are watching this, he adds. Let's see if your tears are any use to those who sent you here. The video has been downloaded more than 100,000 times, mostly in Iraq, says Smyth.
SMYTH: It's spread all over social media.
AMOS: The interview, the exchange, is a rare moment of human contact, he says, in a very brutal war.
SMYTH: When both sides believe they are fighting a war to not just protect themselves, not just protect families, it's to protect a way of life, to protect their belief in a religious system, when you have both sides like that, then the enemy has been completely reduced and dehumanized.
AMOS: This sectarian hatred is spreading across the region, says Smyth, even as international diplomats are urging Syria's warring sides to settle their differences at a peace conference in Switzerland. Deborah Amos, NPR News, Beirut.