Replaces H.R. McMaster with John Bolton as National Security Advisor

Trump announced via Twitter that he was replacing National Security Advisor H.R. McMaster with John Bolton, a hawkish former UN ambassador known for advocating military intervention in Iran and North Korea. The move signaled a shift toward a more aggressive foreign policy and removed one of the remaining 'adults in the room' who had restrained Trump's impulses.

"I am pleased to announce that, effective 4/9/18, @AmbJohnBolton will be my new National Security Advisor." — Twitter, March 22, 2018