Commentary: Jim Mattis has issued a warning to be heeded by all Americans

Former Secretary of Defense Jim Mattis is on book tour. In a number of interviews about his bestseller titled, “Call Sign Chaos: Learning to Lead,” he has deplored the deeply divided state of our country.Mattis is blunt, writing: “What concerns me most as a military man is not our external adversaries; it is our internal divisiveness. We are dividing into hostile tribes cheering against each other, fueled by emotion and a mutual disdain that jeopardizes our future, instead of r