President Donald Trump shakes hands with Army Lt. Gen. H.R. McMaster, his national security adviser, at Trump's Mar-a-Lago resort in Palm Beach, Florida, in February. Nicholas Kamm/AFP/Getty Images hide caption

Tom Bowman
News Brief: U.S. Strategy On Assad Lacks Details, North Korea Aggression
President Trump leaves the podium at Mar-a-Lago in Palm Beach, Fla., Thursday night after the U.S. fired a barrage of cruise missiles into Syria in retaliation for this week's chemical attack against civilians. Alex Brandon/AP hide caption
Morning News Brief: Chemical Attack In Syria, China's President In The U.S., Beyonce
Defense Secretary Expresses Concern Over Russian Support For Taliban
Trapped Civilians Complicate U.S. Efforts in Northern Syria And Iraq
U.S.-backed Syrian Democratic Forces, made up of an alliance of Arab and Kurdish fighters, regroup on the northern outskirts of Deir Ezzor as they advance to encircle the ISIS bastion of Raqqa on Feb. 21. Delil Souleiman/AFP/Getty Images hide caption
Big Changes And Major Dilemmas Loom In Next Phase Of ISIS War In Syria
Trump's New National Security Adviser Is Known For Speaking His Mind
President Trump (right) shakes hands with Army Lt. Gen. H.R. McMaster at Trump's Mar-a-Lago estate in Palm Beach, Fla., on Monday. Trump called McMaster "a man of tremendous talent and tremendous experience" as he announced that he would replace Michael Flynn as national security adviser. Susan Walsh/AP hide caption