John Bolton on Tuesday became the third national security adviser to resign from the position during President Donald Trump's tenure.

Homeland security expert Juliette Kayyem joined Boston Public Radio Wednesday to talk about Bolton's removal, and his replacement.

"In the history of national security advisers and presidents, this is the most number of national security advisers in such a short period of time. No president has come close to firing three national security advisers," she said.

Kayyem believes that Bolton was hazardous in the role, but she said she isn't confident that the next appointed national security adviser will be any less dangerous.

"Bolton is a dangerous ideologue. I don't feel any pity for him being gone, but I also don't feel any safer that he's gone because of the question of who's going to replace him," she said, calling the Trump administration's process of appointing advisers and cabinet members "broken."

"President Trump is his own lawyer, his own communications staff and now he's his own national security adviser. The entire system is broken," she said. "The vetting process is, 'Are you on Fox News and do you say something nice about the president? If you do then you're good.'"

Kayyem is an analyst for CNN, former assistant secretary at the Department of Homeland Security and faculty chair of the homeland security program at Harvard University’s Kennedy School of Government.