Protecting the borders from espionage is essential. It’s something else to deny students because they are Chinese and hope to pursue a STEM degree in the United States.

© Rachel Wisniewski for The New York Times

Protecting the borders from espionage is essential. It’s something else to deny students because they are Chinese and hope to pursue a STEM degree in the United States.

The 1970s era of academic exchange began as a form of diplomacy. “People were curious about us, inviting us to their homes,” one former student remembers.

The 1970s era of academic exchange began as a form of diplomacy. “People were curious about us, inviting us to their homes,” one former student remembers.

© KT Kanazawich for The New York Times

Students said the latest move had upended their plans and intensified their fears.

As applicants in Beijing wait to see how sweeping the new action might be, one says the United States is making people too scared.

Secretary of State Marco Rubio said the students who will have their visas canceled include people with ties to the Chinese Communist Party and those studying in “critical fields.”

Students said the latest move had upended their plans and intensified their fears.