AdvertisementTrump Revokes Clearance Of Ex-CIA Boss Brennan, Puts Other Critics On NoticeAugust 15, 2018Tamara KeithfacebookEmailFormer CIA Director John Brennan at a congressional hearing in 2017. President Trump revoked Brennan's security clearance Wednesday, claiming he was "erratic." Brennan has been one of Trump's harshest critics in the national security community. (Getty Images)