“I need to get my degree safely,” the student told me. A Chinese national and doctoral candidate in social sciences at an American university, she’d recently heard that her social-media messages might be checked at the U.S. border. “Safely,” for her, meant a series of measures to avoid anything incriminating: She downloaded the end-to-end-encrypted messaging app Signal and set her messages to disappear after 24 hours, and she also no longer sends sensitive links in group chats—that is, anything involving Donald Trump, Israel, or DEI. She’s not the only one with a new sense of anxiety. Whenever her Chinese classmates talk about American politics at the campus cafeteria or in school, she told me, they lower their voices.

The day she and I spoke, June 10, was the final day of China’s university-entrance exams. She had been watching videos on the Chinese social-media platform Weibo of students back home being cheered on to the examination venues by crowds, of flowers being handed out, and of police asking motorists not to honk so that students could concentrate on their test. She said it felt as though the whole society was behind them, willing their success.

Earlier that day, she had received an email from her U.S. university department that provided an emergency plan for sudden visa revocation. The memo included a recommendation to make a contact list of immigration attorneys, and a notice to save both digital and printed copies of the plan. The email even came with guidance on securing temporary housing, implying that students needed a backup plan. Seeking clarification, students were told that they were responsible for covering any costs.

“We’re students; we don’t have lawyers,” she said. “We just don’t know how to navigate this.”

The administration’s actions had led to rising defensiveness and pessimism in her circle. And the housing advice prompted her to ask, half-jokingly, “Are we at war, or what?”

I spoke with five Chinese nationals for this article: an undergraduate, a master’s student, two people pursuing Ph.D.s, and one newly tenured faculty member. None of them wanted their name used. The younger students—less tethered to the United States—spoke openly about considering other options: countries with clearer rules, less visa ambiguity and angst. The doctoral students were more invested in trying to stay and, despite growing uncertainty, wanted to build a career in the United States. I have been writing about China, from Beijing, for the past few years, so I’m used to my sources asking for anonymity. People in China are acutely conscious of the limits of permissible speech there and how crossing those lines can affect their future. But this time, I wasn’t speaking with Chinese people in China; I was speaking with Chinese people in the United States. This time, they weren’t afraid of their own government back home, but the American one they were living under.

The grounds for their fear were not hypothetical. The United States is trying to draw a red line to keep out Chinese students it perceives as a national-security threat. The problem is that no one knows exactly where the line is.

From 2009 to 2022, Chinese students were the largest group of international students in the United States. At peak, in the 2019–20 academic year, some 370,000 Chinese students were enrolled at American universities. Numbers have since tapered off, initially because of the pandemic. Then, on May 28, Secretary of State Marco Rubio announced that the U.S. would begin “aggressively” revoking visas of Chinese students, including those studying in “sensitive” fields or with Chinese Communist Party links.

A Republican-backed bill currently in Congress goes further still—it would ban visas for all Chinese nationals looking to study in the United States. The authors of the bill point to China’s 2017 National Intelligence Law, which requires citizens to support intelligence-gathering for their home country even when abroad. Although the GOP bill may not pass, its hard-line stance underlines the level of uncertainty students now face.

In June, President Donald Trump appeared to give Chinese students in the U.S. a reprieve when he announced that they would remain welcome, pending a putative trade deal with China. But by making plain that the students were a token in his trade war, Trump only increased the uncertainty of their predicament.

The Chinese students I spoke with were intently parsing official edicts in an effort to work out which course subjects were sensitive and which weren’t. What I detected from my conversations with them was their sense of being caught in a guessing game. A formerly innocuous decision about whether to leave the U.S. for a trip now seemed like a high-stakes gamble. In the country that they had believed offered the freest and most resource-rich research environment, they were now carefully policing their own discourse. Back in China, students know the score, but they never expected to be contending with these worries in the United States. In its nationalist rhetoric and sweeping use of state-security justifications, the U.S. was starting to mirror aspects of the very system it has long denounced.

“The White House website looks like a Chinese government site now,” the newly tenured professor told me, referring to the oversize portraits of President Trump.

Read: The Trojan Horse will come for us too

When the social-sciences Ph.D. student first applied to study abroad, she regarded the U.S. as the world leader for research in her field. Among her peers, the opportunity to pursue postgraduate studies at an American university was the runaway first choice. She had graduated from China’s elite Tsinghua University, known especially for its STEM programs, so America’s close ties between research and business, with proximity to venture capital, were part of the draw. “You want to see your work realized in real life,” she told me.

That optimism has faded as she’s seen the heightened U.S.-China tensions filtering down into life on an American campus. “You always walk with your Chinese identity,” she said. “It’s hard to isolate yourself from ongoing chaos.”

Even during the first Trump administration, some of her friends from China had sensed that the environment in the U.S. was growing more hostile. Those who were studying subjects with potential military applications, such as robotics and information systems, applied to European programs instead. But they faced difficulties there too: After initially receiving offers from universities in the European Union, they saw their visa prospects vanish into a bureaucratic thicket of vetting checks. European countries have also increased their scrutiny of Chinese students who conduct STEM research with potential military, as well as civilian, applications.

A Chinese student at New York University told me that he’d considered joining a “No Kings” rally this month but decided to stay away, fearing that he might endanger his visa. “It’s becoming the same as the situation in China,” he said. “You can talk about foreign policy, but not domestic policy.”

After his positive experience of a year at a U.S. high school, he’d had no hesitation about applying only to American universities—which ranked highly for the engineering degree he expected to graduate with. But he told me he might have applied elsewhere if he had known how quickly American government policy would turn against international students, and Chinese students in particular. Now he was living with the same visa-status anxiety facing friends of his—Chinese nationals or people raised in China—who were seeing their renewals denied or delayed with vague demands for additional paperwork. He wasn’t privy to their full applications, but he believed that these obstacles were a result of their Chinese ties.

The NYU student wasn’t alone in sensing a shift. A master’s student told me that during her reentry to the U.S. last year, she was pulled aside into what Chinese students colloquially call the “little black room,” an immigration-interview room at the airport. This reflects a pattern of heightened scrutiny at the border that began under the Biden administration, but Chinese citizens are familiar with the “little black room” because it’s what security officers back home use if they suspect some kind of anti-government conduct.

The U.S. immigration officer checking her passport said she could leave after the student declared she was studying graphic design. If her answer had been computer science, she believed from accounts she’d seen on social media, “I’d definitely stay there for a few hours.”

A Ph.D. student in a Republican state who has planned a research trip out of the country this summer told me that her adviser expressly warned her not to get involved in protests or post anything pro-Palestine online, and to watch her driving speed. She said these warnings began last year, as red states anticipated Trump’s return to power. Fearing that she could be denied reentry, she was ready to cancel her trip entirely if official U.S. announcements became more hard-line.

The master’s student has exercised similar precautions. Knowing that social-media accounts are checked and have a bearing on visa issuance, she restricts herself to sharing internet memes that broadly hint at her frustration without specifically criticizing federal immigration policy. Memes live in a “gray area,” she said. Being vague makes them “safer.”

Read: No more student visas? No problem.

This moment is by no means the first time that the U.S. has viewed Chinese students with suspicion. In the 1950s, American officials placed the scientist Qian Xuesen under house arrest and eventually deported him. The U.S. authorities came to regret their action: Back in China, Qian became the father of its missile-and-space program.

Relations began to thaw in the ’70s after President Richard Nixon’s historic visit to China. In 1979, China’s leader Deng Xiaoping met with President Jimmy Carter and agreed to step up scientific exchanges. Implicit in the U.S. government’s motivation was a belief that if Chinese students were exposed to the benefits of democracy, they would recognize what they were missing and create a political constituency for reforming China.

This spirit of engagement persisted through China’s entry into the World Trade Organization in 2001. By then, the aspiration of studying abroad had been normalized for Chinese young people—as a personal choice. The wildly popular 1990s TV show A Beijinger in New York, which aired on the state broadcaster China Central Television, was a testament to that generation’s curiosity about the outside world. This cultural trend continued into the early 2000s, when “Harvard Girl” Liu Yiting became a national sensation as an American-educated success story. Her parents’ best-selling book chronicling how they’d raised her was a model for millions of other Chinese families, all hoping to nurture their own Harvard Girl.

The recently U.S.-tenured professor I spoke with came of age during China’s relatively liberal era of the late 1990s and early 2000s, under the premierships of Jiang Zemin and Hu Jintao, so he had earned his master’s at a very different time in U.S. politics, during Barack Obama’s presidency. His own research field is national security—and he acknowledged that the United States had legitimate concerns about Chinese government–sponsored actions, citing instances of intellectual-property theft.

“I just don’t think the administration is dealing with this in a targeted way,” he told me. Refusing students a visa simply because of links to the CCP was too broad, he argued, given China’s condition as a one-party state in which almost every institution has a formal party presence. He supported the vetting of students, based on solid evidence and with due process.

In the student-deportation cases he was following, some were being removed because they had once been charged with a minor offense, even if the charge had subsequently been dismissed. “It’s shocking,” he said. “Their status was revoked overnight.” He said, in most instances, the Chinese students’ universities received no prior notice.

“My guess is the government has adopted some kind of screening system,” he said, but one that seemed to him crude and unreliable. “There are a lot of false positives.” (I requested comment from Immigration and Customs Enforcement and its parent agency, the Department of Homeland Security, but received no response.)

This student’s home country, he added, was not making things easier for Chinese students abroad. “The National Intelligence Law is not doing us a favor,” he said: The law includes penalties for obstructing intelligence work, which puts Chinese nationals abroad in a very awkward position. I asked what he’d do if the Chinese government asked him to share information; he said he’d call an American lawyer.

On RedNote, a social-media app popular with Chinese students, posts continue to circulate about deportations over such minor infractions as speeding tickets. Some fear that if they travel abroad, they will be denied reentry to the United States. Chinese students are familiar with surveillance, scrutiny, and expansive definitions of national security. They just didn’t expect all of that from the U.S. government, as well.