The world no longer cares who is king of the castle in Northern Ireland

From the vantage point of Washington, the viciousness in Short Strand or Ardoyne must seem rather insignificant

Louis MacNeice once chided his fellow Irishmen for deluding themselves that the world cared "who was king of your castle". He wrote as a man gazing scornfully on Ireland from the vantage point of London. MacNeice was contemplating a world threatened by the rise of Hitler and was clearly impatient with the tribal drum-beating of Ulster. Here was European civilisation about to be engulfed by fascism, but from across the Irish sea came the unforgiving mantras of an island gazing relentlessly inwards.

The Irish exile with a political consciousness generally falls into one of two categories. They either become bitterly impatient with the rhetoric of division and adopt MacNeice's attitude of impatience, or they become partisans for one side or the other. I have never felt inclined to become a partisan, but on occasion I've suffered from the delusion that the world really cares who is king of our castle. That was back when I was based in Belfast and some eruption of horror would bring the international television crews flooding into the Europa Hotel. It would last a few weeks, and then the strange accents would vanish, and the quarrel would resume its unspectacular, murderous routine.

MacNeice had it right about the self-delusion. You had to leave Belfast and live in a place where history was really stretching its legs to understand how small our quarrel looked to the rest of the world. Very few people cared who was king of our castle. I moved from Belfast to South Africa. While some among my fellow islanders were shooting and bombing or making excuses for shooting and bombing, South Africans were working out a constitutional settlement. While our two traditions shouted slogans, the blacks, whites, coloureds and Indians of South Africa found a language of common purpose.

Then everything changed in Ireland. I could hardly believe the news from home. Out of town and out of touch, I had missed some fundamental changes. There were at last politicians willing to take enormous risks. Hume, Trimble, Adams, Irvine. Each faced a moment of decision when the interests of tribe collided with an unfamiliar demand to act for the common good.

For a few years in the late 1990s the world really did care. An American president and prime ministers in Britain and the Republic invested their political reputations in the dangerous swamp of Ulster politics. The most powerful man in the world, Bill Clinton, sent one of the most patient men in the world, George Mitchell, to help to get a deal in Belfast. Ireland was going places, north and south. My compatriots in the Republic voted to abandon the territorial claim on Northern Ireland, an act of national self-confidence that removed the alibi used by hardline Unionists to avoid accommodation with the south.

David Trimble went to Dublin and met the Taoiseach and sat down in a powersharing government with Sinn Fein – at last something to show the world that would inspire admiration, not scorn. Those were the days. Now after a summer of vicious street violence, the return of sectarian murder, a police force exhausted and demoralised, we wonder where the good days have gone. Ulster boils again, and there are crisis talks in London. In a week where George Bush was addressing the UN on the possibility of a new conflict in the Middle East, the politicians of Ulster were arguing over whether a "ceasefire monitor" should be deployed to keep intra-communal thuggery and paramilitary violence from erupting into a wider conflagration.

From the vantage point of Washington the viciousness in Short Strand or Ardoyne must seem insignificant.It is hard to imagine the US ever again taking such a pronounced involvement. That makes things more difficult for Tony Blair. He knows the degree of threat the Good Friday Agreement faces, but there are limits on the power of a British Prime Minister. What he cannot do is make the politicians of Northern Ireland trust each other.

Pressed by the hardliners in their respective constituencies the leaders of Unionism and Republicanism have constantly looked over their shoulders. They made important concessions but they have never given the impression that being in government together is anything other than a painful labour. The people of the loyalist and Republican heartlands sense the unpalatable truth: their leaders may sit around the same cabinet table and do the jobs of ministers, but the trust needed to make peace take firm root is absent.

You might say that after 30 years and more than 3,000 deaths, it's a miracle they sit in the same room at all. We have been saying that for several years now, but the physical fact of power-sharing is no longer enough. I don't believe David Trimble and Gerry Adams are about to embrace each other publicly, but how long can power-sharing survive in the current bitter mood?

The paramilitaries on both sides continue to make a mockery of the peace. The IRA moves towards decommissioning yet its punishment squads dole out terror. On the loyalist, side the murder gangs are back on the prowl and stoking factional hatred. Friends tell me the atmosphere on the streets reminds them of the months leading up to the eruption of the Troubles in August 1969. Nobody imagined the bitterness would wither away quickly. But we didn't expect it to get worse.

The Government's response is to suggest the deployment of a ceasefire monitor whose purpose would be to single out those groups who are breaching the peace. The Unionists broadly support the idea, the Republicans believe it is designed to harm them. The public here might simply ask why the gunmen on all sides don't just disarm and go home.

The simple enough answer is that weapons still confer power. For loyalist paramilitaries there is no chance of a major electoral gain. They have no rationale for disbanding their military wings. The Republicans may be the biggest political winners of recent years, but they too remain addicted to the brute power that the word IRA can inspire. Critically, neither loyalist nor republican gunmen feel inclined to retire while there remains the danger of a fresh explosion of sectarian clashes. It is a wretched circle. The presence of gunmen gives the politicians reason to mistrust each other, the mistrust feeds into the civilian population who look to the gunmen.

The new monitor will have the toughest job in politics. At what point does he decide one or other paramilitary group has effectively broken the ceasefire, and risk the agreement by suspending their political wing? It will take a brave figure who understands the dynamics of conflict. Step forward the hero of South Africa's transition, Cyril Ramaphosa. He has worked in Ireland and has the wisdom to shout stop. The trouble will be to persuade him that the task is not impossible. Send him soon or we will be back to that country of competing victimhoods whose shrill rhetoric drove Louis MacNeice to such scorn.

The writer is a BBC Special Correspondent.