Sunni militants are reportedly now in control of most of Iraq's largest oil refinery, which provides gas to about 25 percent of the entire country.

The ISIS fighters began shelling the refinery in Baiji on Tuesday night and into Wednesday morning. An official told Reuters from inside the facility that "the militants have managed to break in to the refinery. Now they are in control of the production units, administration building and four watch towers. This is 75 percent of the refinery." The government, however, maintains that its forces still have control. According to Iraq's counter-terrorism spokesman Sabah Nouri, government forces killed 50-60 insurgents and set 6 or 7 militant vehicles on fire to stave off the attack. 

Abu Bakr al-Baghdadi, head of ISIS.
AP/Iraqi Interior Ministry

If ISIS starts siphoning gas for its own purposes -- as militants did during the sectarian insurgency of 2004-2007 -- the group would have a steady source of income and make conditions even worse for Iraqis, who could see power outages and long lines at gas stations as a result of the siege.

Meanwhile, Iran has vowed to help Iraq's Shiite government fight ISIS. Iranian President Hassan Rouhani said on Wednesday that "we declare to all superpowers, their mercenaries, murderers and terrorists that the great Iranian nation will not miss any effort in protecting these sacred sites." Thousands of Iranians have already volunteered to help defend Iraqi shrines.

Turkey has also commented on the situation, casually dropping that it might no longer be opposed to a totally autonomous Kurdish state in Iraq. The Iraqi Kurdish population has long sought independence, and their militia was the first to take a stance against ISIS when clashes began last week. The Kurdish fighters took the opportunity to secure control of the city of Kirkuk, as they have hoped to do for years. Turkey is also concerned by reports that Turkish oil workers have been kidnapped by ISIS fighters, and India is troubled by similar reports about its own nationals working in Turkey. 

As Iran offers its army to Iraq, Washington maintains that it won't send in troops beyond the 275 soldiers deployed to protect U.S. assets in Iraq. It is still, however, considering other options, such as targeted air strikes or setting up special forces to deal with the escalating situation.