Former CIA Director Michael Hayden told Fox News Sunday that up to 5,000 American troops will be in Iraq by the end of the year.

He's basing that estimate on the number of support troops it will take to carry out the air campaign against ISIS.

The Hill:

“In terms of intelligence, surveillance, reconnaissance, logistics, advice, command and control assistance, tactical air control parties, look I’m betting we’re up close 5,000 by the end of the year,” he said on “Fox News Sunday.”

Hayden explained he doesn’t think they will be “combat maneuver units,” but predicted U.S. special operations forces could wind up on the ground in Syria. 

“I think we will at some point. It might be through covert action rather than more overt activity,” he said. “I actually think we will end up with small American special operations forces active within this broad theater in Syria and Iraq.” 

The most difficult plan to execute, Hayden said, will be training and arming the Free Syrian Army, or vetted moderate opposition groups in Syria. 

The U.S. would be “starting from zero” to create a “substantial” combat power, said Hayden, who served as director of the CIA under President George W. Bush and director of the National Security Agency under Bush and President Bill Clinton. 

“That is a result of an American policy not to help that group over the last few years,” he said.

Hayden's estimate presupposes the Obama administration will vastly expand the air campaign against ISIS. This would take not only additional ground based aircraft being based in Iraq, but also more aircraft carriers stationed in the Gulf. Currently, there is only one carrier - the George H.W. Bush - with the Carl Vinson scheduled to relieve it next month. It's possible that the president could double our sea-based aircraft by maintaining both ships in the Gulf.

But the president has not shown any inclination to increase American air power - yet. That may come in November once the mid terms are out of the way.