The Trump administration has revoked the visas of four more international students at Columbia University in recent days, the school announced late Sunday. Reasons for the cancellations were not clear. The federal government has terminated the visas of hundreds of foreign-born students involved in the pro-Palestinian protest movement that engulfed college campuses last year — though not all of them. Others have claimed to be caught in the crosshairs or targeted for criminal infractions, such as “minor traffic violations,” said Columbia Provost Angela Olinto. “The university was not notified of these status terminations and only became aware of them through...