Iraq Scrambles to Defend Baghdad, Iran Joins Battle

Iran Says Forces Join Battle Against Advancing Sunni Insurgents Threatening Capital, Holy Cities.

ISIS militants are shown after allegedly seizing control of an Iraqi army checkpoint in northern Iraq

Iraq’s government girded to protect the capital from advancing insurgents, as Iranian security officials said their forces had joined the battle on Baghdad’s side and the U.S. weighed military assistance, including airstrikes.

Iraq edged closer to all-out sectarian conflict as Kurdish forces took control of a provincial capital in the oil-rich north on Thursday and Sunni militants threatened to march on two cities revered by Shiite Muslims and the capital.

The deteriorating situation in Iraq—a key global oil supplier—reverberated through financial markets Thursday, sending oil prices sharply higher, pushing U.S. stocks lower and igniting the latest rally in safe-haven bonds.

Faced with the threat of Sunni extremists eclipsing the power of Iraq’s Shiite-dominated rulers, Shiite Iran sprang into action to aid its besieged Arab ally. It deployed Revolutionary Guards units to Iraq, Iranian security officials said. At least three battalions of the Quds Forces, the overseas branch of the Guards, were dispatched, the security officials said.

Some U.S. military officials cast doubt on the report that battalions of Iranian Quds Forces had deployed to Iraq, saying only militias controlled by or allied with Iran have been mobilized to fight alongside Iraqi forces.

One Revolutionary Guards unit that was already in Iraq fought alongside the Iraqi army against the Islamic State of Iraq and al-Sham, an offshoot of al Qaeda rapidly gaining territory across Iraq, the security officials said.

They offered guerrilla-warfare advice and tactics and helped to reclaim most of the city of Tikrit on Thursday, the security officials said. Two units, dispatched from Iran’s western border provinces on Wednesday, were tasked with protecting Baghdad and the holy Shiite cities of Karbala and Najaf, they said.

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