In March, the Trump administration began revoking the F-1 visas of international students, including some of those who attend the college where I teach history. My students were afraid. They had come to America for an education, and they suddenly felt that they were living on borrowed time. The administration’s policy isn’t merely upsetting to me as a teacher; it is also a betrayal of America’s values and an un-American attack on our free-speech norms.

The government began by targeting a few prominent individuals. On 8 March, Mahmoud Khalil, a Palestinian graduate student, was arrested at his home by Immigration and Customs Enforcement (ICE) agents. He was accused of having served as a spokesman for protests at Columbia University and distributing “pro-Hamas propaganda.” Khalil is a permanent resident of the United States with a green card and his wife, who is currently pregnant, is an American citizen.

A few weeks later, on 25 March, Rümeysa Öztürk, a Turkish doctoral student and Fulbright scholar at Tufts University, was seized on the street by plainclothes ICE agents, an event captured in a chilling video recording. The Department of Homeland Security claimed that Öztürk had “engaged in activities in support of Hamas,” but unlike Khalil, she was not an activist. Her only “activity in support of Hamas” seems to have been her co-authorship of an op-ed in the student paper criticising her school’s refusal to condemn Israel.

Two days after Öztürk was seized, Secretary of State Marco Rubio made a statement to reporters justifying her arrest:

If you apply for a visa to enter the United States and be a student, and you tell us that the reason you are coming to the United States is not just because you want to write op-eds but because you want to participate in movements that are involved in doing things like vandalizing universities, harassing students, taking over buildings, creating a ruckus, we are not going to give you a visa.

There is no evidence that Öztürk vandalised universities, harassed students, took over buildings, or created any kind of ruckus. Khalil and Öztürk were not the only targets. By early April, thousands of students across the nation received notice that their F-1 student visas had been revoked by ICE. Without visas, they would be forced to return home, their degrees incomplete.

Students took their cases to the courts. In his defence of the administration’s conduct, Rubio cited the 1952 Immigration and Nationality Act, Section 212(a)(3)(C) of which gives the government the power to deport foreigners whose presence risks “serious adverse foreign policy consequences for the United States.” But many of the arrested students appear to be guilty of only minor infractions, many of which took place years ago. It’s hard to see how an old traffic ticket poses any kind of foreign-policy risk.