Former CIA Director Gen. Michael Hayden on Sunday said he predicts there could be nearly 5,000 U.S. personnel on the ground overseas by the end of the year to fight the Islamic State in Iraq and Syria (ISIS).

“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.”

ADVERTISEMENT

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 said the U.S. military campaign to defeat ISIS will likely last three to five years even if it is successful.