In recent weeks, Molotov cocktails, bricks and bottles have met barricades and water cannons as towns and cities in Northern Ireland faced some of their worst rioting in years. Mobs made up mainly of teenagers from both loyalist and republican neighborhoods have clashed with police, who struggled to keep both sides apart at a “peace line” in Belfast.
The anger in Northern Ireland has many sources. Loyalists, who want to remain part of the U.K., want to know why, in a time of COVID restrictions, authorities pursued no prosecutions after crowds defied lockdown rules to gather for the recent funeral of a prominent member of the Irish Republican Army. A police crackdown on criminal gangs in loyalist neighborhoods has also pushed defiant young people into the streets.
But underneath all of this is the growing fear among loyalists that Brexit will increase the likelihood of Northern Ireland’s leaving the U.K. to reunify with the Irish Republic, a member of the E.U. The controversy of the moment centers on the question of borders. As part of Brexit negotiations with the E.U., U.K. Prime Minister Boris Johnson agreed to avoid reimposition of the land border that separates Ireland from Northern Ireland–and, therefore, the E.U. from Britain. Instead, the two sides agreed on the so-called Northern Ireland Protocol, which establishes a trade boundary in the Irish Sea.
There is still haggling to be done over the movement of food, animals and plants across that boundary to ensure that products leaving the U.K. meet E.U. legal, regulatory and health standards. There are also outstanding questions ranging from the future of steel and aluminum tariffs to the movement of pets across the border. The E.U. had argued that an alignment of standards on the manufacture of many products would mean fewer and faster border checks, but Johnson’s government is reluctant to make commitments that make it harder for the U.K. to sign future trade deals with other countries.
All of this leaves loyalists in Northern Ireland feeling pushed to the European side and fearful of a unified Ireland, while facing product shortages as new customs processes slow the movement of goods. This surge of anger comes as the governing and staunchly loyalist Democratic Unionist Party (DUP) preps for a serious electoral challenge next year. To fend off criticism that the DUP, supporters of Brexit, is responsible for Northern Ireland’s current predicament, its leaders have demanded that the protocol be scrapped entirely. If that’s not enough to blunt criticism of the party, a fragmentation of its voting bloc could leave the Northern Ireland Assembly in the hands of nationalists led by a Sinn Fein First Minister. That’s a nightmare scenario for loyalists and a serious challenge to the Good Friday Agreement, which brought peace 23 years ago.
How will Johnson respond? Many in the U.K. have moved in favor of Brexit in recent months, easing pressure on him for bold action, and Britain’s successful vaccine rollout should continue that trend. But Johnson can’t ignore Northern Ireland’s troubles, because they may become worse.
An end to the violence will require cooperation between loyalist and republican leaders, the British and Irish governments, and U.K. and E.U. negotiators charged with finding a way to ease the flow of trade to limit the risk to Ireland. Don’t expect quick progress. And there is no border fix that can ease tensions between those who hope for a unified Ireland and those who fear it.
This appears in the April 26, 2021 issue of TIME.