A former deputy director of the CIA said on "CBS This Morning" Wednesday that it would take 100,000 ground troops to effectively respond to the Islamic State of Iraq and Syria, or ISIS.

"Unless the coalition is willing to put more ground troops into Iraq and possibly into Syria, there is very little we can do to respond," said CBS News senior security contributor Michael Morell, the former No. 2 at the CIA.

Morell made the comments following ISIS' release of a video Tuesday purportedly showing captive Jordanian pilot Lt. Muath Al-Kaseasbeh being burned to death. The killing led Jordanian officials to execute two Iraqi al Qaeda-linked prisoners.

Morell said the will to commit such a large number of troops "simply does not exist" in the U.S. or in Western Europe.

Following the execution of Japanese hostage Kenji Goto over the weekend, President Obama said the United States is working to rescue an American woman held by ISIS.

"I think the United States would be willing to spend a lot of money and a lot of resources to find this American woman," Morell said. "... And I'm sure that everything is being done, but it's difficult to do."

If countries remain hesitant to engage the terror group by putting boots on the ground, Morell said there is another possible strategy.

"Take out the leadership. This is a hierarchical organization, a small leadership. That would make a difference," Morell said.

But it's difficult to accomplish, he said, because it would require knowing the position of the group's leaders at a particular time.

"That takes very, very good intelligence," Morell said.

In what appeared to be a message to Jordan for the close relationship between King Abdullah and Mr. Obama, CBS News' Charlie D'Agata reports, the terror group released a video purportedly showing Al-Kaseasbeh walking through the aftermath of coalition airstrikes against ISIS.

"A lot of clips of F-16s in this video, so I think they're saying, 'We're not going to stop because you're bringing this high technology to bear against us,'" Morell said.

Morell said that's not all the extremists were trying to accomplish by releasing the video.

"They're trying to intimidate, which is what they've been trying to do all along with these beheadings," Morell said.

On the "CBS Evening News" Tuesday, Morell doubted that ISIS' intimidation tactics would work.

"The first beheading that they did was what brought the international community together the first time, and I think this will likely backfire too," said Morell. "I think there will be an outcry internationally."