The WSJ is reporting that Iran has deployed two battalions of the Quds force, the elite, international branch of its paramilitary Revolutionary Guard, to Iraq to back up the mostly Shiite government in Baghdad:

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.