Meetings between top military brass and civilian leaders are nothing new. But experts say the scale of the gathering, the haste with which it was called and the mystery surrounding it are particularly unusual. “What’s mystifying is why it’s on such short notice, why it’s in person and what else might be involved,” he said. Trump didn’t seem to know about it when he was asked by reporters during an Oval Office appearance later that day. “It’s a way of demonstrating,” Clark said, “that this is important.”Associated Press writer Sylvie Corbet in Paris contributed to this report.