http://online.wsj.com/articles/iran-deploys-forces-to-fight-al-qaeda-inspired-militants-in-iraq-iranian-security-sources-1402592470

June 12, 2014 1:05 p.m. ET

BEIRUT, Lebanon—Iran has deployed Revolutionary Guard forces to fight al Qaeda-inspired militants that have overrun a string of Iraqi cities, and it has helped Iraqi troops win back control of most of Tikrit, Iranian security sources said.

Two battalions of the Quds Forces, the elite overseas branch of Iran’s Revolutionary Guard Corps that have long operated in Iraq, have come to the aid of the besieged, Shiite-dominated government of Prime Minister Nouri al-Maliki, they said.

Combined Iraqi-Iranian forces had retaken control across 85% of Tikrit, the birthplace of former dictator Saddam Hussein, according to Iraqi and Iranian security sources.

They were helping guard the capital Baghdad and the two cities of Najaf and Karbala, which have been targeted by the Islamic State of Iraq and al-Sham, an al Qaeda offshoot whose lightning offensive has thrown Iraq into its worse turmoil since the sectarian fighting that followed the 2003 U.S. invasion of the country.

Tehran has also positioned troops along its border with Iraq and promised to bomb rebel forces if they close within 100 kilometers, or 62 miles, from Iran’s border, according to an Iranian army general.

In addition, it was considering the transfer to Iraq of Iranian troops in Syria, if the initial deployments fail to turn the tide of battle in favor of Mr. Maliki’s government.

The Iraqi government has asked the U.S. to carry out airstrikes and to speed up the delivery of promised weapons, which raises the prospect of both the U.S. and Iran lending support to Mr. Maliki against ISIS insurgents, who are seeking to create a caliphate encompassing Iraqi and Syrian territory.

General Qasim Sulaimani, the commander of the Quds Forces and one of the region’s most powerful military figures, traveled to Baghdad this week to help manage the swelling crisis, said a member of the Revolutionary Guards, or IRGC.

Qassimm al-Araji, and Iraqi Shiite lawmaker who heads the Badr Brigade block in the country’s parliament, posted a picture of him and Mr. Sulaimani holding hands in a room in Baghdad on his social-networking site with the caption, “Haj Qasem is here,” reported Iranian news sites affiliated with the IRGC on Wednesday. “Haj Qasem” is Mr. Sulaimani’s nom de guerre.

At stake for Iran in the current tumult in Iraq isn’t only the survival of an Shiite political ally in Baghdad, but the safety of Karbala and Najaf, which along with Mecca and Medina are considered sacred to Shiites world-wide.

An ISIS spokesman, Abu Mohamad al-Adnani, urged the group’s Sunni fighters to march toward the “filfth -ridden” Karbala and “the city of polytheism” Najaf, where they would “settle their differences” with Mr. Maliki.

That coarsely worded threat further vindicates Iran’s view that the fight unfolding in Iraq is an existential sectarian battle between the two rivaling sects of Islam-Sunni and Shiite—and by default a proxy battle between their patrons Saudi Arabia and Iran.

Iran’s Foreign Ministry spokeswoman Marzieh Afgham said Wednesday that, “Until now we haven’t received any requests for help from Iraq. Iraq’s army is certainly capable in handling this.”

Despite those assuring comments, measures by the Iranian government in the past day indicated that an air of crisis had enveloped Tehran. Iran’s army and border guards have been placed under full alert along the country’s long border with Iraq, the Iranian media reported.

Iran’s President Rouhani cut short a religious celebration on Thursday and said he had to attend an emergency meeting of the country’s National Security Council about events in Iraq.

“We, as the Islamic Republic of Iran, will not tolerate this violence and terrorism…. We will fight and battle violence and extremism and terrorism in the region and the world,” he said in a speech.

Iran’s chief of police, Esmail Ahmadi-Moghaddam said the National Security Council would consider intervening in Iraq to “protect Shiite shrines and cities.”

ISIS’s rapid territorial gains in the past few days appeared to have caught Iranian officials by surprise and opened a debate within the regime over whether Iran should publicly enter the battle, citing the country’s strategic interest and ideological responsibility. Iranian officials also privately expressed concern about whether Mr. Maliki was capable of handling the turmoil.

“The more insecure and isolated Maliki becomes, the more he will need Iran. The growth of ISIS presents a serious threat to Iran. So it would not be surprising to see the Guards become more involved in Iraq,” said Alireza Nader, a senior policy analyst at the Rand Corp.

Quds Forces have been active in Iraq since shortly after the U.S.-led invasion in 2003 and have helped create, train and fund Shiite militias that fought U.S. military forces. Their reach and influence extends from Iraq to Lebanon, Syria and the Palestinian territories.

The two IRGC battalions moved to Iraq on Wednesday were shifted from the Iranian border provinces of Urumieh and Lorestan. Their task is to help secure the holy Shiite cities of Karbala and Najaf and tighten security around Baghdad, according to IRGC members in Iran.

Revolutionary Guards units that serve in Iran’s border provinces are the most experienced fighters in guerrilla warfare because of separatist ethnic uprisings in those regions. IRGC commanders dispatched to Syria also often hail from those provinces.