Dear Mr Trump, you'll regret the loss of international students like us

Heavy rain swept through Cambridge, Massachusetts, last Thursday, washing the pavements clear of last week's graduation confetti. Inside Harvard's quiet dorms and still-lit libraries, a different cleansing began.

- Hugh Pearson & David Gayle

In a terse letter, homeland security secretary Kristi Noem revoked the university’s licence to host international students - “effective immediately”. Harvard now has 72 hours to surrender every record - formal file or scribbled note - that might link a non-immigrant student to protest, violence or some unnamed offence. More than a quarter of the student body could be expelled for the passport they carry.

Panic rippled through WhatsApp. Should we leave tonight or lie low? A volunteer lawyer opened an emer-gency Zoom; the waiting room overflowed. Rumours spread of laptops searched at Boston’s Logan airport and of social media posts kept as evidence. Even friends from “safe” countries - Canada, Germany, France - refreshed airline sites, hop-ing a swift exit might spare them the encounters with Ice (Immigration and Customs Enforcement) now common for students in Boston.