Programming Note: Former Vice President Dick Cheney sits down with Sean Hannity to give his take on the latest military action in Syria. Don't miss a "Hannity" exclusive, Wednesday at 10p ET.

Retired four-star Gen. Jack Keane joined Megyn Kelly on a bonus hour of "The Kelly File" live tonight to react to the breaking news that the U.S. Air Force and Navy, joined by Arab allies, launched an intense bombing campaign in Syria against multiple ISIS targets.

WATCH: Amateur Video Claims to Show U.S. Airstrikes Against ISIS in Syria

Characterizing it as a "significant night," Keane noted that the U.S. has four Arab Muslim countries - all Sunni - attacking a Sunni terrorist organization.

"That did not come easy," Keane said, pointing out that UAE, Saudi Arabia, Jordan and Bahrain should be very helpful allies in the fight against ISIS and should aid President Obama in bringing other nations into the anti-ISIS coalition.

A fifth Arab ally, Qatar, on the other hand, has long been a financial backer of not just ISIS, but also Hamas. Keane said he is not convinced that Qatar is suddenly going to "change their stripes."

BREAKING NEWS: U.S. Military and Allies Conduct First Airstrikes in Syria

Keane said he thinks that ISIS believed that the U.S. would never actually strike them in Syria, possibly because of the lack of international response to dictatorial Syrian President Bashar al-Assad using chemical weapons on his own people.

As for the issue of how long the U.S. will bomb ISIS targets in Syria, Keane stated, "as long as those targets are accessible, we'll continue to attack."

He reiterated, however, that a combination of ground forces and airstrikes will likely be necessary to actually push ISIS out of the territory it has conquered.

Watch the clip from "The Kelly File" above.

Watters’ World: How Would College Students Deal With ISIS?