President Trump said he left the NATO summit feeling differently about the alliance than when he arrived, after countries showed their appreciation for the U.S. “I came here because it was something I’m supposed to be doing, but I left here a little bit different,” Mr. Trump said at his post-NATO press conference Wednesday. He said he watched other world leaders at the summit talk about the love and passion they have for their countries. “I’ve never seen quite anything like it,” he said. “They want to protect their country, and they need the United States, and without the United...