The moment the clock struck 2 p.m. Monday, some three dozen members of Columbia University faculty and staff, decked out in neon-orange hi-vis vests, shuffled into formation in front of the entrance to the school’s West Lawn and locked arms. They braced for the impending threat of a police sweep of the now internationally famous anti-war encampment, a nucleus 70 tents strong, with a handful of students quietly, peacefully milling among them. The faculty phalanx was not the only protective layer formed around those student protesters, who have, in recent months, been doxxed, threatened, suspended, attacked with a chemical weapon,...