Peter Bergen, is CNN's national security analyst, a vice president at New America, a professor of practice at Arizona State University, and the author of "Manhunt: The Ten-Year Search for bin Laden from 9/11 to Abbottabad."

(CNN) President Trump is picking on the wrong guy if he thinks the revocation of John Brennan's security clearances is going to intimidate or silence him. The man who is in many ways the architect of the war on militant jihadists is not going to be easily bullied.

Former CIA director Brennan is not just any critic of Trump: unlike many others, he doesn't come from the left. In fact, Brennan is the engineer of some of the most aggressive American efforts to eliminate jihadist terrorists.

In person, Brennan , who grew up in a devout Catholic working class family in New Jersey, is serious, even stern, not big on small talk and intolerant of BS.

President Barack Obama trusted Brennan deeply on counterterrorism issues and Brennan played an important role in the decision to carry out the operation that killed Osama bin Laden in Abbottabad, Pakistan, in 2011.

Key Obama Cabinet officials, such as Secretary of Defense Robert Gates and Vice President Joe Biden, advocated against authorizing a US Navy SEAL raid in Pakistan because of all the risks involved in such an operation, which were compounded by only circumstantial evidence that bin Laden was living in Abbottabad.

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