A former director of the CIA described the greater likelihood that terror attacks on U.S. soil would come from an American resident as "a witch's brew."
Appearing on CNN's "State of the Union," Michael Hayden, who served under President George W. Bush and stepped down in February 2009, said the "new flavor of threat" was different from "the traditional high-threshold mass casualty attack" that would originate in the al Qaeda stronghold in the tribal regions of Pakistan.
"It's much more difficult for us to defend against those kinds of attacks," Hayden said of terror plots originating from franchises in the U.S.
"They will be less lethal if they do succeed," he said. "But they will unfortunately almost certainly be more numerous."
Mike McConnell, the former Director of National Intelligence under Bush, commended the Obama administration for how it has been handling the evolving threats.
"My observation is the new administration has been as aggressive, if not
more aggressive, in pursuing these issues, because they're real," McConnell said.
"Regardless of which side of the political spectrum you come from or what your political views might be, these threats are very real and very serious and we have to deal with them in a very serious way," he said.
Hayden stressed that even though the homegrown terrorists would be more amateur in conducting "low-threshold" attacks, the threat was "almost like penalty kicks in soccer."
"No matter how good your goalie is, sooner or later this ball is going to get into the back of the net," he said.
McConnell said he would most worry about a chemical or biological attack from al Qaeda.
"The most likely event is going to be an explosion. They want death and
destruction and blood and mayhem," he said. "That's what they strive for. But
there are other things that they could consider.
"And of course, one of the things I'm identified with is worrying about someday they'll figure out how to cause us harm through a cyber attack, against what I call the soft underbelly of the country," which could disrupt financial or transportation sectors, McConnell added.
"We have to take the fight to them, make them spend most of their day worrying about their survival rather than figuring out ways to threaten our survival," Hayden said.
Of the White House efforts including drone strikes that continue to rankle Pakistan, Hayden said, "I've seen over two administrations, and I thank God every day for the continuity."