The key question, it seemed, was how far these men would go to remain British. On another occasion, Gibson told me he would accept a democratic vote for Irish unity it if it came to that. Others, however, are more strident. Many loyalists feel a sense of decline as Catholics have gained more rights and upward mobility; young loyalist men in interface areas who used to be guaranteed factory jobs by virtue of their identity now face high unemployment and a sense that their standing in society has eroded. Such grievances seem to only reinforce people’s sense of identity. Loyalist paramilitaries feed off this to gain recruits, though according to the police, these groups are more often involved in organized crime than in politics. Still, in East Belfast, I observed how one paramilitary — the U.V.F. — had the capacity to stir up sectarian passions.

Last summer, in advance of the July 12 celebrations, members of Belfast’s republican-led City Council voted to remove a pyre made of wooden pallets in East Belfast — set up for the coming bonfire night — saying it was illegally on city property, namely the parking lot of a recreation center. Local loyalists responded angrily and vowed not to allow the city to remove the pyre, resulting in a standoff that, for days, became the main news story in town. At a demonstration one evening that drew hundreds of people to the site of the pyre, I met a number of masked young men who told me they were protecting the pyre from being dismantled. Jamie Bryson, the loyalist activist, spoke to the crowd. “Standing exposed tonight is the actual agenda of Belfast City Council,” he said. “And it is the total demolition of every aspect of Protestant unionist and loyalist culture,” he went on. “We will not have it!” This inspired a fervent round of applause. “No surrender!” shouted a woman next to me who wore a shirt that said “Me Wrong?” on it. “This is British land, and it will stay British land,” she then told me.

Police officers said the standoff was whipped up by the U.V.F. In a letter to the City Council, the police warned that any attempt to remove the pyre would “cause a severe, violent confrontation, orchestrated by the U.V.F.” and that the “use of firearms during such disorder cannot be ruled out.” Ultimately, the police did not move in. This was, Bryson later wrote in an online newsletter, a “momentous and hugely symbolic victory within the context of the larger cultural war.”

On the bonfire night, I went to another pyre on a barren plot next to a peace wall in West Belfast, where my tour guide, Robert, had taken me. As the sky slowly darkened, a D.J. played pulsing techno. Drunken teenagers milled around. A small, impromptu marching band of revelers formed. They sang a U.V.F. tune at the top of their lungs: “On my gravestone, carve a simple message: ‘Here lies a soldier of the U.V.F.’ ” I spoke to one woman among them who told me that this was all in good fun, just an expression of loyalist culture. But you couldn’t help noticing that the pyre that was about to be lit had been bedecked with flags of the Republic of Ireland.