Things look a little different in the US these days. Leaves are turning, the football stadiums are full, and children are planning their trick-or-treating routes; there are also masked men snatching people off the streets, while the US military has had boots on the ground in four major cities, another state, and the nation’s capital. Last week, Illinois governor JB Pritzker went on national television and suggested federal immigration agents can be held legally accountable for how they conduct themselves. Elected officials such as Representative Marjorie Taylor Greene of Georgia have spoken openly about a “national divorce.” It’s impossible to look around and not wonder whether the US is teetering on the brink—though of what, is the question. Ordinary, reasonable people are openly talking about whether the country is on the verge of something comparable to a slow-rolling civil conflict, if not something worse. They’re not alone. Historians of those conflicts are worried. They’re not concerned about a full-blown civil war, featuring rival divisions of the US Army staging set-piece battles over territory, but something else that even the experts have a hard time putting their finger on. Familiar frameworks, like the US Civil War or the Troubles in Northern Ireland, probably present too square a peg for the present round hole. “I’m creating a new hole for the peg,” says Robert Pape, a professor at the University of Chicago who has been studying political violence for the past three decades. Since 2022, he’s been working on a new concept he calls “violent populism,” which he thinks could better represent the country’s current moment. He describes it as something “between civil war and nasty politics as usual.” In “violent populism,” there is a certain level of demand for—or acceptance of—violence. Real-life examples can range from January 6 rioters who battered police officers to Luigi Mangione superfans calling for the executions of executives. President Trump’s actions count here too, Pape says: It doesn’t help matters that the Trump administration continues to refer to its political opposition as enemy combatants or uses explicitly violent and militaristic language to describe the current moment. “What Trump is doing is creating more and more permission structures for people to carry out violence for his goals,” Pape says, pointing to the pardoning and sentence commutations of January 6 rioters and the president’s encouragement of military generals to be more aggressive by using American cities as “a training ground” to fight “the enemy from within.”