Columbia University students who refuse to end their protest against Israel's war in Gaza say university officials have threatened to bring in the National Guard and police to sweep their encampment. It comes after Columbia authorized the New York Police Department to arrest more than 100 pro-Palestinian student demonstrators who had camped out on Columbia's main lawn to protest the war and demand their school divest from companies with ties to Israel. The student protesters said they would not engage in negotiations with the university "until there is a written that the administration will not be unleashing the NYPD or...