President Trump announced a major shakeup in his national security team on Thursday, tapping Mike Waltz to be his United Nations ambassador while Secretary of State Marco Rubio will fill the national security adviser post on an acting basis. “I am pleased to announce that I will be nominating Mike Waltz to be the next United States Ambassador to the United Nations,” Trump wrote on Truth Social. “From his time in uniform on the battlefield, in Congress and, as my National Security Advisor, Mike Waltz has worked hard to put our Nation’s Interests first. I know he will do the...