A 29-year-old Palestinian refugee raised in Syria, Khalil wanted to get involved in the on-campus activism against the war, but he was nervous.

Khalil faced a dilemma common to international students: He was in the United States on a F-1 student visa. His ability to stay in the country hinged on his continued enrollment as a full-time student.

But participating in a protest — including the encampment that cropped up on Columbia’s lawn last month — meant risking suspension and other punishments that could endanger his enrollment status.

“Since the beginning, I decided to stay out of the public eye and away from media attention or high-risk activities,” Khalil said. “I considered the encampment to be ‘high risk’.”

He instead opted to be a lead negotiator for Columbia University Apartheid Divest, a student group pushing school administrators to sever ties with Israel and groups engaged in abuses against Palestinians.

“I’m one of the lucky ones who are able to advocate for the rights of Palestinians, the folks who are getting killed back in Palestine,” Khalil said, calling his advocacy work “literally the bare minimum I could do”.

Khalil explained he worked closely with the university to make sure that his activities would not get him in trouble. Based on his conversations with school leaders, he felt it was unlikely that he would face punishment.

Still, on April 30, Khalil received an email from Columbia administrators saying he had been suspended, citing his alleged participation in the encampment.

“I was shocked,” Khalil said. “It was ridiculous that they would suspend the negotiator.”

Legal jeopardy

However, a day later — before Khalil could even appeal the decision — the university sent him an email saying his suspension was dropped.

“After reviewing our records and reviewing evidence with Columbia University Public Safety, it has been determined to rescind your interim suspension,” the short, three-sentence email said.

Khalil said he even received a call from the Columbia University president’s office, apologising for the mistake.

But legal experts and civil rights advocates warn that even temporary suspensions could have severe consequences for students who depend on educational visas to stay in the country.

Naz Ahmad, co-founder of the Creating Law Enforcement Accountability & Responsibility project at CUNY School of Law, told Al Jazeera that when a student-visa holder is no longer enrolled full time, the university is obliged to report the student to the Department of Homeland Security within 21 days.

That department oversees immigration services for the US government. Students must then make plans to leave — or risk eventual deportation proceedings.

“If they don’t leave right away, they would begin to accrue unlawful presence,” Ahmad said. “And that can affect their ability to apply again in the future for other benefits.”

Ann Block, a senior staff lawyer at the Immigrant Legal Resource Center, told Al Jazeera that most schools have a designated official to monitor the status of international students.

“They generally are international student advisers, and they’re the ones that help people get into the school, get their visas to come to the school from abroad initially and normally help advise them,” Block explained.

Even outside of an academic context, non-citizens face the possibility of heightened consequences should they choose to protest.

While non-citizens enjoy many of the same civil rights as US citizens — including the right to free speech — experts said that laws like the Patriot Act may limit how those protections apply.

Passed in the aftermath of the September 11 attacks, the Patriot Act includes broad language that could be used to interpret protests as “terrorist” activity, according to civil rights lawyer and New York University professor Elizabeth OuYang.

And the law empowers the government to restrict immigration to anyone engaged in such activity, she added.

“Section 411 of the Patriot Act bars entry to non-citizens who have used their ‘position of prominence with any within any country to endorse or espouse terrorist activity’,” OuYang said.

“And what constitutes terrorist activity? And that’s where the secretary of state of the United States has broad discretion to interpret that.”

Avoiding the front lines

The high level of scrutiny towards the campus protests has amplified fears that such consequences could be invoked.

Criticism of Israel, after all, is a sensitive subject in the US, the country’s longtime ally.

While a study released in May indicated that 97 percent of US campus protests were peaceful, politicians on both sides of the aisle have continued to raise fears of violence and anti-Semitic hate.

Just last week, Republican Representative Andy Ogles introduced a bill called the Study Abroad Act that would take away student visas “for rioting or unlawful protests, and for other purposes”.

He cited the recent wave of university protests as a motivation for sponsoring the legislation and compared the demonstrators to terrorists.

“Many elite American universities have damaged their hard-earned reputations by opening their doors to impressionable terrorist sympathisers,” Ogles told The Daily Caller, a right-wing site.

Some international students who spoke to Al Jazeera said the charged political atmosphere has forced them to avoid the protests altogether.

“We cannot take the risk as international students to even be caught at the scene at all,” said one student journalist at the University of California, Los Angeles (UCLA), who requested anonymity in order to speak freely.

Another student added that he does not even feel comfortable reporting live on the protests for UCLA Radio, the student-run station where he works.

Other students explained that they have pursued peripheral roles in the protests, offering supplies and services instead of manning encampments and clashing with police.

An undocumented student at Columbia University, originally from Mexico, said she joined a supplies “platoon” to help distribute materials and move tents. She asked to be identified only by her first initial, A.

“None of it means no risk,” she said. “I feel I could find my way out. But I’m not necessarily going to put myself in front of a cop.”

On April 29, student organisers at Columbia even warned their classmates over megaphones to leave the encampment if they were attending school on a visa, for fear of suspensions. A, the undocumented student, said her parents also encouraged her not to participate in the protest.

“It just is so hard to be a bystander when it would be going against my convictions,” she explained. “I cannot watch children die.”

A chilling effect

One Columbia student from South Africa, who asked for anonymity out of concern for her immigration status, said it was, in fact, the US tradition of campus activism that attracted her to the school.

“I came here knowing that there were protests against apartheid South Africa. There were protests in ‘68 about Vietnam, about Harlem,” she said.

But after facing disciplinary warnings for her activism this year, she explained she had to scale back.

“The combination of xenophobia and extreme surveillance make how I decide to participate in this movement different from if I were a citizen,” she said.

The police crackdowns on campus protests have also had a chilling effect, several international students told Al Jazeera.

Estimates put the number of campus protesters arrested over the last month north of 2,000. Just this Thursday, 47 people at the University of California, Irvine, were taken into custody, according to campus officials.

Olya, a Columbia undergraduate from Thailand, was among those who participated in the encampment at her school in its early days. She provided Al Jazeera with her first name only, also citing immigration concerns.

But when school administrators set a deadline for the protesters to disband or else face suspension, Olya decided she had reached her limit.

“That was when I stopped going to the encampment more frequently because it made me realize that you really don’t know what admin’s gonna do,” Olya said.

“I think that my fears of possibly getting arrested sort of overshadows my interest in advocacy and activism in general. Especially in this country.”