Former National Security Adviser Michael Flynn failed to disclose trips to the Middle East during his security clearance process, according to a letter from House Democrats to Flynn, his business partners and special counsel Robert Mueller.

“[Mueller] needs to look into the fact that Flynn not only had all sorts of missions during his security clearance or on the documentation of his security clearance, but when he was doing the security clearance process, he was visiting nations that he was not disclosing,” said national security expert Juliette Kayyem on Boston Public Radio today.

Flynn met with Saudi Arabian government officials and a Russian government agency in the Middle East in 2015 to talk about building nuclear power plants. He did not disclose this meeting while he sought security clearance for his position as national security adviser.

Kayyem said she suspects Flynn will be the “weak link” in the Russia investigation, meaning he’ll be the one to collaborate with investigators.

“Mike Flynn is facing a lot of problems, and he could hope that the president pardons him, but that won’t pardon state crimes — who knows if there [are] any—  or he could go to trial, presumably, and hope for the best, or he could begin to start to talk,” she said. 

Kayyem voiced her suspicions about the meeting between Donald Trump Jr. and a Russian lawyer that Trump Jr. originally claimed was about the process of adoption and later said was about Hillary Clinton’s fitness as a presidential candidate.

“I think the most important part of this, of course, is that meeting that involved Donald Trump Jr. and the alleged discussion about adoption,” she said. “Something happened in that meeting.”

Kayyem said she thinks that Jared Kushner, Paul Manafort and Michael Flynn are the three individuals with Trump ties who are in the most perilous positions during this investigation, and are therefore most likely to talk.

“I think that meeting and obstruction of justice are real, and I think that if you’re Jared Kushner, Paul Manafort or Michael Flynn, one of you gets the golden egg. You get immunity,” she said “And who is it going to be? I don’t know.”

National Security expert Juliette Kayyem is the founder of Kayyem solutions, host of the SCIF podcast and a contributor to CNN and WGBH. To hear her interview in its entirety, click on the audio player above.