Though former Defense Secretary Jim Mattis only mentions his last boss, President Trump, in the opening pages of his new book, the Washington establishment seems certain the tome on leadership is directed at him, with one observer calling it “mainly a 100,000-word subtweet.” Mattis says he won’t discuss a sitting president, though it seems clear he disdains Trump’s leadership style. But he is scathing about a former president in Call Sign Chaos: Learning to Lead, which is released today, and he doesn’t hesitate to name him: Barack Obama. The former general's opinion of Obama, for whom Mattis was head of...
