On Sunday the US involvement in Iraq, in its current manifestation, escalated:

The United States sent attack helicopters into combat against Islamic State targets west of Baghdad on Sunday, the first time low-flying Army aircraft have been committed to fighting in an engagement that the Obama administration has promised would not include “boots on the ground.”

The U.S. Central Command, in a statement about U.S. activities against the Islamic State in Iraq and Syria, provided few specifics about the helicopters. But they were likely AH-64 Apache attack helicopters, which were deployed to Baghdad International Airport in June to provide protection for U.S. military and diplomatic facilities.

This is significant for a couple of reasons. First, it underscores what a lot of us have said from the beginning of this misadventure, that airpower alone is a necessary but insufficient element in stopping the advance of ISIS. Second, while not technically on the ground the AH-64s are Army and they are based in Iraq and carrying out attacks within Iraq. Third, they are doing so without a Status of Forces Agreement passed by the Iraqi parliament.

If you recall, the absence of this SOFA was used by Barack Obama as a reason to withdraw US troops from Iraq and an excuse for us not having a presence on the ground when the ISIS offensive started:

Q Mr. President, do you have any second thoughts about pulling all ground troops out of Iraq? And does it give you pause as the U.S. — is it doing the same thing in Afghanistan?

THE PRESIDENT: What I just find interesting is the degree to which this issue keeps on coming up, as if this was my decision. Under the previous administration, we had turned over the country to a sovereign, democratically elected Iraqi government. In order for us to maintain troops in Iraq, we needed the invitation of the Iraqi government and we needed assurances that our personnel would be immune from prosecution if, for example, they were protecting themselves and ended up getting in a firefight with Iraqis, that they wouldn’t be hauled before an Iraqi judicial system.

These pilots are flying under the protection of an executive order issued by the previous prime minister, Nour al-Maliki. An executive order that was offered to Obama by Maliki in 2011 in order to guarantee that US troops would remain in Iraq.

Unlike high performance aircraft which can operate above the range of air defense systems available to ISIS or as part of strike packages that can shut down more capable air defense systems, the AH-64 can do 182 mph. Downhill. With a tail wind. And it is much more vulnerable.

Although the administration has repeatedly said that no “ground forces” would be used in the fight against the Islamic State, the use of the AH-64 represents a blurring of that promise.

The helicopters carry a two-man crew and with their missiles and powerful canon, increase the amount and accuracy of the firepower that the U.S. military can bring to bear against the Islamic State in support of Iraqi ground troops. But because helicopters fly relatively “low and slow,” the Obama administration is taking on greater risk in terms of exposing U.S. forces to casualties, White said.

“The Iraqi air force just lost a brand new Russian helicopter (to Islamic State ground fire). So it’s significantly higher risk for whoever is flying the mission,” said White. “It’s certainly crossing another threshold. The U.S. is conducting strikes that are directly involved in combat.”