Expert shares sobering warning as Trump allows key spy tool to expire: 'Wake up'

A national security expert flagged the impact of one of President Donald Trump's moves that effectively allowed a key U.S. spy tool to expire.

During an appearance on CNN, Leon Panetta, the former CIA director under former President Barack Obama and White House chief of staff during the Clinton administration, expressed concern about the expiration of a key part of the Foreign Intelligence Surveillance Act.

House lawmakers refused to reauthorize Section 702 of FISA earlier this month in response to Trump's pick for acting director of national intelligence, Bill Pulte. When Trump refused to drop Pulte, FISA lapsed, and Panetta explained what losing FISA means for national security.

"You want to create a vulnerability in terms of our national security? Prevent FISA from taking effect," Panetta said. "Because what that does is it allows terrorists to be able to communicate in this country."

FISA provides the U.S. with the "ability to basically capture that kind of communication so that we know what terrorists are up to and what threats our country is facing," Panetta added.

"With FISA shut down right now, without question, this country is very vulnerable to some kind of terrorist attack," Panetta said. "People have got to wake up. The president's got to wake up."

Panetta said that he understands "the political games that go on sometimes," but "at this moment, our national security is what is most important to the president, to the country and to Congress."