In Australia, foreign students are said to bring in more than 30bn Australian dollars a year ($20bn; £16bn), and it is a market that Australian universities have been targeting for years.

Andrew Norton, professor of the practice of higher education policy at Australian National University in Canberra, says the country has been trying to attract foreign students from Asia since the 1980s.

Australia has some distinct advantages for these students, he says. “We are in much the same time zone, the climate is attractive, and there is the possibility of migrating here.”

But the government in Canberra has not helped the sector very much, if at all, during this crisis. Prime Minister Scott Morrison even went as far as saying that foreign students should consider going back to their home countries if they could not support themselves during the lockdown, external.

That message is hardly likely to encourage new students to feel welcome in future, and that matters, says Prof Norton, because “there is a pipeline effect”.

“If students don’t start a degree course this year, then they are not here for three years,” he says, meaning universities are going to be feeling the pressure of lost income for years to come, and not only in Australia.

In the US the university sector is a massive business. Some of the oldest and most famous colleges have billions in reserve, massive endowments, and a reputation that means they can charge students top dollar. But even they are suffering being closed now.

Many overseas students in the US are demanding rebates for lost lessons, and American universities make a small fortune from having students on site. Catering and accommodation are huge earners. Students in the UK have also been calling for refunds.

Vijay Govindarajan, Coxe distinguished professor at Tuck School of Business at Dartmouth College, says: “I don’t see how we can reopen and have campus classes this fall [autumn]”.