Others who are in the country are effectively trapped. They can’t leave, lest they be denied re-entry. Indeed, many are being told to stay put by their institutions. On Friday afternoon, MIT sent an email to its international scholars advising them to “consider postponing any travel outside of the U.S.” until the executive orders had been clarified. Harvard University sent a similar email late Saturday, adding that since “the executive order also contemplates that additional countries could be added to the banned list … all foreign nationals should carefully assess whether it is worth the risk to travel outside the country.”
International travel is a major and inescapable part of modern science. Many scientists have foreign collaborators, which “substantially increases the pace of discovery and ideas,” says Plotkin. Researchers are expected to attend conferences abroad to share their work. Some have no choice but to fly to visit remote field sites, or unique paleontological digs, or sites of disease outbreaks, or one-of-a-kind facilities like telescopes and observatories.
For many Iranian students in the U.S., restrictions were already harsh. “When we get a visa, it’s usually a single-entry visa,” says Farshad Nasiri, who is studying for a Ph.D. in mechanical engineering at George Washington University. “If I were to leave the States and visit my family, I’d have to reapply for a visa and go through the whole process. I didn’t want to risk it so, for four years, I haven’t travelled. Even before Trump, it was already pretty rough; this will make it even more difficult.”
The new policies could also isolate American institutions from major sources of foreign talent. “The upshot is that, until further notice, science departments at American universities can no longer recruit Ph.D. students from Iran—a country that … has long been the source of some of our best talent,” wrote Scott Aronson (Mehraban’s supervisor), on his personal blog. “This will directly affect this year’s recruiting season, which is just now getting underway.”
Every scientist whom I contacted for this story had tales of colleagues who left and are being denied re-entry, friends who were applying for jobs in the U.S. and now reconsidering, departments that have lost prospective hires, international collaborators who were planning to travel to the U.S. for research but have been denied entry, and foreign academics who are planning to boycott American conferences. “It’s going to destabilize a lot of labs, faculty recruitments, contributions from conferences,” says Houra Merrikh from the University of Washington. “This will have a big impact at all levels in science.”
Merrikh is an immigrant herself. When she was three, her family fled the Iran-Iraq war and settled in Turkey. At 16, she moved to Texas with a green card, no family, and no money; she worked through several poor-paying jobs so she could pay for a college spot. Now a naturalized citizen of 14 years and a professor of microbiology, she studies the evolution of infectious microbes.