The police arrived in force at dawn on Saturday, with orders to clear “infiltrators” from the Gaza war protest camp at Northeastern University in Boston.
Within an hour, more than 100 people were under arrest, students and non-students alike, and many of their tents flattened or removed. A large counter-protest then formed, as officers from the state police in tactical gear hauled off their suspects. The scene was one of confrontation, and chaos.
Northeastern campus administrators said they were compelled to call police as infiltration by outsiders “led to a clear escalation in tensions” and that an antisemitic slur had been heard – something the protesters deny.
As the campus protests stretch into a second week across the US, Northeastern is among many colleges that have now taken the decision to crack down hard and refused calls to divest from companies involved in Israel's military.
Columbia in New York squashed the very first camp on 18 April, citing “a harassing and intimidating environment for many of our students”. Since then they have blanked protester demands and announced suspensions for some students.
The student response has been escalation, and on Tuesday dozens occupied and damaged a university building, leading to officials threatening expulsions. On Tuesday night, police moved onto campus in force at the university's request to end the occupation.
Other colleges, however, have shown that confrontation, chaos and escalation can be avoided.
The story at Northwestern University, just outside of Chicago, is entirely different to that of Northeastern. Its protest camp appeared on Thursday morning. University administrators responded by banning tents and calling in campus police.
They stopped short of calling in state police and no arrests were made, and the campus officers eventually left.
On Monday, administrators announced a deal: protesters were to be allowed to stay until the end of classes on 1 June if they remove tents and limit those taking part to students and others affiliated with the university.
They stopped short of agreeing to stop investments in Israeli companies and arms manufacturers, but agreed to restart an investment committee and increase transparency over its approximately $13.7bn (£11bn) endowment.
Northwestern also promised to fund places for two Palestinian faculty members and five Palestinian students.
A truce appears to be holding – at least for now. Northwestern and Northeasten are both private colleges, and both in left-leaning, liberal states. So why were their responses to essentially the same situation and demands so different?
Lauren Lassabe Shepherd, a historian at the University of New Orleans, said the pro-Palestine protests have not reached the fever pitch or level of violence seen during anti-war demonstrations in the 1960s and 70s – where some students were calling for the overthrow of the US government.
She said that in some cases, however, calling in outside police forces had dramatically raised the stakes.
“Nearly all American universities have campus police, who are full-time, uniformed and can make arrests,” she said.
“Calling in municipal police or National Guard troops is a high-risk strategy.”
Scenes of police clashing with protesters have been splashed across social media, and outsiders and observers can also get caught up in the camp shutdowns. At Emory University in Atlanta, professors were among those arrested by city and state police last week, including Noelle McAfee, chair of the university's philosophy department.
Ms McAfee told the BBC that she was observing what she described as a peaceful protest when police started to move in and the protesters began to move. She began filming police hitting a protester, she said, and noticed chemical irritants in the air.
“It was really disturbing. I started yelling ‘stop it', and I was trying to take a video. One of the cops stood up and told me I need to step away… I froze in place.” She was then arrested. Hundreds of other arrests have been reported at universities all around the country, even as other disputes have been resolved without law enforcement.
On Tuesday, protesters and administrators reached an agreement at Brown University, similar to Northwestern's, which promised to hold a vote on divestment from weapons manufacturers in the autumn. And a camp at University of California, Berkeley – the epicentre of the 1960s protest movement – has been both largely peaceful and left alone.
Political pressure
Ken Paulson, director of the Free Speech Center at Middle Tennessee State University, said that political pressure, including from high-ranking members of Congress, had forced some administrators into potentially risky moves that in some cases have backfired.
“Increasingly, college presidents are trying to show Congress and the world that they're tough enough to be college presidents,” he said. “And that is so reminiscent of the late 60s, with lawmakers threatening college presidents and insisting that they cannot coddle anti-war student protesters.”
The pressure can be more acute on leaders at private universities, he said, because publicly funded universities are obliged to provide students First Amendment protections.
“At private schools, they don't necessarily have to offer free speech rights,” Mr Paulson said. “So they can't tell legislators that their hands are tied and they can't do anything. They have to navigate these protests strictly with their own policies.”
Time may be on the side of campus administrators.
Mr Paulson said that most students are no part of the protests and are simply trying to get through the year, although graduation ceremonies could provide another protest target. Some universities have already cancelled commencement ceremonies or are considering doing so.
If history is any guide, said Lauren Lassabe Shepherd, “we are going to have an intense next week or two until the spring semester ends”.