President Trump’s national security adviser is leaving the White House in the first major staff shakeup. National Security Adviser Mike Waltz is expected to depart the administration in the coming days. Waltz made embarrassing headlines in March when he mistakenly added a reporter to a Signal chat on military strikes. At the time, the president downplayed the seriousness of the incident and stood by Waltz. But some Trump allies complained that the national security adviser wasn’t loyal enough to the “Make America Great Again” agenda.