I remember in the late 1990s driving around the “bad lands” of south Armagh. The border between Northern Ireland and the Irish Republic was porous. I had read enough about the gun-running and the terrorist groups operating in the area, but what struck me most were the houses, the cars and the satellite dishes.

Back in Belfast, a UK government minister explained. Part of the tactic over the years, he said, was to make the warring sides more comfortable. The more they had to lose personally, the less they would be prone to fight.

Many around the world cite Northern Ireland as the model attempt at conflict resolution. Protestants and Catholics share power at Stormont, with Peter Robinson and Martin McGuinness seemingly enjoying each other's company as first minister and his deputy.

Groups from South Africa to the Basque country are eager to learn the secrets of its success. That is why each outbreak of violence, such as this weekend's during the Orange Order marching season, is so damaging. Each episode opens old wounds and begs a question that the political establishments in Belfast, London and Dublin would rather not be asked. Northern Ireland is safe, and welcoming to visitors. But can reconciliation ever be achieved, or is it just a veneer?

The political language is so different from before. The Police Service of Northern Ireland bears little resemblance to its predecessor, the Royal Ulster Constabulary, which was reviled and feared by many Catholics.

The man in charge of the police force, Matt Baggott, is a tough-talking and, from what I've seen of him, fair-minded officer, who has risen through the ranks from Tooting and Peckham, in south London. Baggott would not in the last few days have called up reinforcements from England, Wales and Scotland lightly, with all the symbolism that this decision entails.

Each year the parades are a potential flashpoint, particularly as many, as if by right, follow routes that take them through Catholic enclaves. Outsiders who have witnessed the bizarre old-fashioned rituals around the marches struggle to understand the passions that surround King Billy's epic victory over the Catholics more than 300 years ago on the “Glorious Twelfth”, 12 July 1690.

As the July marching season approaches, communities brace themselves for problems. What happened last December was arguably more worrying because it did not follow an established pattern. The violence that followed a decision by Belfast city council to change its policy of permanently flying the union flag led to more than a month of violence, much of it in the city centre—the modern, non-sectarian part of the city that businesses and tourism officials like to project as having moved on from the Troubles.

That sudden outburst of fury threatened many of the assumptions of policymakers. Would it undermine the UK City of Culture that was beginning in Derry/Londonderry (note the meticulous official double-designation of the city, to cater to both sides)? Would it, more fundamentally, send tourists and investors scurrying for cover?

The anger had no basis in logic. All the council was doing was aligning its approach to that of UK institutions, which is to fly the flag on 18 government-designated days of the year, including “significant” royal birthdays (including the Duchess of Cambridge's).

Some unionists see in the restrictions on their marches and the curtailment of the flag a link—and an attack on their identity. It is, they say, a mixture of elitism, political engineering and demographics. Belfast city council now has more nationalist members than unionist. The parades commission, they insist, is cleaving in the direction of an establishment that no longer looks after their interests.

As for economics, academic research is inconclusive. Throughout the Troubles, downturns did not appear to make matters better or worse. Yet in the 15 years since the Good Friday agreement, the new establishment has become so successful that those who do not support the principles underlying it feel more marginalised now than ever.

That means those unionists who have not benefited from, or claim not to have benefited from, the new-look Northern Ireland. Some, but by no means all, are economically marginalised. What they share is a sense of disenfranchisement, a concern that it is only a matter of time before Protestants become a minority in “their own country”.

That poses a grave danger because if people feel they have nothing to lose, that they have gained little from “peace”, they will lash out.

Again, emotions are getting in the way of logic. Demographic movements tend to be inconclusive (note Israeli/Palestinian/Arab birth rate arguments). But even if a Catholic majority in Northern Ireland did eventually come to pass, would it necessarily lead to a united Ireland? And if it did, what kind of Ireland would that be? And what kind of constitutional, strategic and minority-rights guarantees would have to be put in place?

On one level, the peace established by the politicians is durable. The prospects of anything approaching a return to the Troubles are remote. However, the components for persistent inter-communal strife are all in place. The number of “peace walls” in Northern Ireland has increased since the Good Friday agreement.

These are blots on the landscape (although they are a regular source of income for taxi drivers from foreign tourists), with the tallest coming in at six metres, and the longest stretching for miles. At a meeting last month with Robinson and McGuinness, David Cameron promised more investment if the walls started to come down.

Then there are the walls of the mind. Only 7 per cent of pupils attend integrated schools. During the recent G8 summit in Northern Ireland, Barack Obama called for more integration.

According to a Belfast Telegraph poll, more than two-thirds of the local population agrees. Yet the onus put on faith schools by successive governments in London does not provide the necessary incentive.

The responsibilities, and perks, of office have taken the sting out of the political elite on both sides of the divide. That is huge progress.

However, this does not mean that peace has been embedded in the minds of the angry few who feel ignored.

By arrangement with the Guardian