Yet not in the States. “There has never been, in the last 40 years, a large scale, coordinated, national—or close to national—student strike,” says Angus Johnston, a historian of student activism and a professor at the City University of New York. He offered two broad reasons why that is the case.

First, Johnston says, many American students aren’t aware of striking as a protest maneuver. That would make it difficult for organizers to orchestrate the huge numbers of participants needed to make it work.

“You need to have an awareness of it as a tactic, because it’s something you can’t just do with a small number of students,” he told me. “If it’s a small number of students, then you just fail your classes, because you’re marked as absent. It needs to be a tactic that can be adopted on a really, really wide scale the first time out.”

The few times it’s been attempted here, that happened. The most prominent postwar student strike in the United States came in the spring of 1970, after National Guardsmen shot and killed four undergraduates at Kent State. Students and faculty around the country—mourning those deaths as well as a similar shooting at Jackson State, and protesting the recent American invasion of Cambodia—struck. They shut down almost 450 campuses and demonstrated on nearly 400 more. A presidential commission from the period estimated that a third of all American campuses were involved somehow.

But even that incident revealed how little American colleges were prepared for strikers. “The reason why, honestly, the shootings happened at Kent State is that the university and the state refuses to shut down the campus when students went on strike,” Johnston says.

But in nations where students strike today, he told me, universities have different protocols: “In Canada, you have a situation where if you get to a certain level of student involvement, you can be confident that in most cases at least the university will be shut down—because that’s the protocol that’s followed.”

This is itself a function of local history and custom. Anglophone students in Canada, especially beyond Quebec, are much less likely to strike than their Francophone counterparts. Some European nations have strong traditions of strikes: Classes in Croatia were shut down as recently as 2009, and planned student boycotts famously helped set off the French civil unrest of May 1968. Yet in Britain, Johnston added by email, “marches and rallies and occupations are far more frequent.” And even in places like Quebec, “student strikes are often quite controversial even among activists.”

But law and history are not the only factors pushing students to avoid striking. Americans don’t strike today, Johnston also believes, in part because they can’t afford to miss class.

“Students in the United States today are living in conditions of economic precarity that didn’t exist in the 1960s,” he said. “As students have gotten poorer on average, tuition has gone up. And so they’re getting squeezed on both sides. They have a lot less ability to withstand the effects of … losing a semester, because if that happens, they’re gonna be screwed.”