His fourth national security advisor
Trump started with Flynn, the McMaster, followed by Bolton.
O'Brien was the special presidential envoy for hostage affairs who has brokered the release of high-profile detainees around the world and worked with Mike Pompeo. He's pictured above.
From Trump:
"I am pleased to announce that I will name Robert C. O'Brien, currently serving as the very successful Special Presidential Envoy for Hostage Affairs at the State Department, as our new National Security Advisor. I have worked long & hard with Robert. He will do a great job!"
