Troubles Ahead in Northern Ireland?

Bonnie Weir, New York Review of Books
Although there is little grassroots support for a wholesale return to armed struggle, Brexit does carry the risk of violence. Any form of Brexit that implies the need for new infrastructure at the border sets the stage for an escalation: customs checkpoints would be easy targets, and if attacked, they would need an armed police presence, creating both additional targets and a sense of regression to the days when Northern Ireland was an open-air prison. In turn, violence could creep into urban areas that are close to the borderlike Derry.