A well-known rabbi at Columbia University and its affiliated Barnard College urged Jewish students Sunday to “return home as soon as possible’’ following pro-Palestinian protests on campus he says have endangered their safety as tensions at the Ivy League school in New York City continue to rise. Rabbi Elie Buechler, director of the Orthodox Union-Jewish Learning Initiative on Campus program at Columbia and the all-women’s Barnard, recommended students stay away from the university until safety conditions have improved substantially. “What we are witnessing in and around campus is terrible and tragic,’’ Buechler said in an online posting. “The events of...