Columbia University asked the New York police department to help clear pro-Palestinian activists after dozens of protesters occupied parts of the main campus library on Wednesday. Claire Shipman, the university’s acting president, said in a statement that protesters had refused to leave the building despite being warned that a failure to comply would result in disciplinary action and possibly arrest for trespassing. “Due to the number of individuals participating in the disruption inside and outside of the building, a large group of people attempting to force their way into Butler Library creating a safety hazard, and what we believe to...