The young CIA analyst waited anxiously for Fiona Hill to pick up her phone. He had dialed her, he recalled, because he wanted to hear a familiar voice and make sure he wasn’t doing something “colossally stupid.” Five years later Hill’s memories of the call are still vivid: the CIA analyst’s voice, which sounded uncharacteristically emotional; the annoying clatter of the Frappuccino machine inside the Starbucks where she was waiting for her morning coffee. Hill stepped into the parking lot. She was on vacation in Hawaii, having just resigned a week earlier from her job in Donald Trump’s White House...