A British freshman at Harvard fears he will not be able to return to the US to complete his degree after Donald Trump demanded it stops teaching international students. Alfred Williamson, 20, from Cardiff, left Boston when the academic year ended two weeks ago to visit family in Denmark, only to wake up on 23 May to dozens of missed calls and messages from loved ones about the decision to prevent the Ivy League university from enrolling or retaining foreign nationals. Approximately a quarter of Harvard’s 30,000-strong student body comes from abroad. The university filed a lawsuit last week challenging...