1. Defense Secretary Jim Mattis took pains to walk back President Trump’s threat of an imminent strike against the Assad regime in Syria.

Speaking before the House Armed Services Committee, Mr. Mattis said that retaliation for a suspected chemical weapons attack on Douma had to be balanced against the threat of a wider war between Russia, Iran and the West. British and French officials were also discussing military options.

We interviewed survivors of that attack and reviewed videos and flight records to verify what occurred. “It was a scene that you don’t want anyone to have to see,” said one man who heard people run into the street, yelling: “Chemicals! Chemicals!” At least 43 people were killed.