Boston | Just before the Trump administration announced that it would bar international students from Harvard University, staff met with graduating seniors at the Kennedy School of Government, congratulating them on their degrees – and on surviving the chaos of recent months.

Then, within minutes of the meeting’s end, news alerts lit up the students’ phones. Chaos was breaking out again: Kristi Noem, the homeland security secretary, had notified Harvard that its permission to enrol international students had been revoked.