But not everyone cheers as the parades pass by. For Northern Ireland’s Catholic community, the Twelfth isn’t a celebration, but a provocation. Many Catholics see the parades as triumphalist braggadocio by Protestant supremacist organizations. They see anti-Catholic bigots taking over public spaces, playing chauvinistic tunes (“Oh give me a home / Where there’s no Pope of Rome,” begins one popular song) and displaying the emblems of loyalist paramilitaries that terrorized Catholics for decades. Rather than cheer the parades when they pass their homes, many Catholics protest them. Keeping paraders and protesters apart often requires large police operations, yet confrontations have still led to riots at parades throughout their history, including in 2012, 2013, and 2015.

Conflicts over parades are one of the outstanding issues of the Northern Irish conflict. Though the 30-year period of violence that killed over 3,600 people—euphemistically called the Troubles—formally ended with the signing of the Good Friday Agreement in 1998, conflict between mostly-Protestant Unionists, who wish to remain in the U.K., and mostly-Catholic Nationalists, who wish to unite with Ireland, continues. Today, cultural issues, such as parades, flags, and language, remain major sources of tension between the two sides. A quarrel between the DUP and Sinn Féin, the largest Catholic party, over state support for the Irish language was a principal reason the two parties failed to reach an agreement to restore the devolved provincial government in early July 2017.

In many ways, parades and other issues of cultural representation highlight what’s at stake in the conflict as a whole. Parading disputes, like the conflict in general, represent a fundamental disagreement between two nationalities about identity, territory, belonging, and control. At issue in fights over parades, therefore, is much more than whether or not a group of people walk down the road. Even the uncontested parades (over 80 percent of the total last year) touch on the sensitive central question in Northern Irish politics: Who should rule this land, the United Kingdom or the Republic of Ireland? The paraders’ answer—the U.K.—clashes with the aspirations of many Catholics, who seek a united Ireland, finally free of Britain’s control. Fundamentally, conflicts over parades are conflicts over the national character of the state and public space. Should this state, this city, this town, this neighborhood, even this street reflect the culture, values, interests, and desires of Protestants or Catholics? These questions will only gain salience as Brexit erases the U.K. and Ireland’s shared EU membership, and raises the possibility of restoring an enforced border between the two countries.

This zero-sum worldview fuels the politics of Northern Ireland, and the DUP is very much a product and producer of the us-or-them political culture. Their Protestant voters feel under siege, and any gain made by Catholics is experienced as a loss for them. Take the Protestant experience of the peace process. The negotiations that successfully ended the Troubles are hailed worldwide as a signal diplomatic achievement, but for many local Protestants it feels like an unrelenting defeat. Polls show that Protestants believe that peace has benefited Catholics more than them, which has led to increasing disenchantment with the agreement. Many feel that Catholics are using their political power to push any sense of Britishness off the island. Protesting parades and imposing restrictions on them are understood as a primary way that Catholics are chipping away at Protestant and British life in the province. This helps explains why the defense of parades and other cultural issues often dominate Protestant politics in Northern Ireland.