Let the Unionists march - it's the only way they can protest at their betrayal

The barricades are going up, the contingency plans are being reviewed, police leave is being cancelled. In the province of Ulster, the marching season is upon us again. And community relations are as poisoned as ever.

So are the Unionists' public relations. Respectable suits, 17th century rhetoric, bowler hats and swords. Nothing could be more calculated to alienate moderate English opinion than the spectacle of Orangemen on parade.

That is the trouble with moderate English opinion. The moderate English are a post-religious, post-historical people, who instinctively assume that the world ought to be recreated in their own consumerist image. When other nations and races resist this condescension, the moderate English tend to respond with an uncomprehending peevishness. Thus it is with the Middle East, George Bush's America, and with Ulster.

The Orangemen who will be marching over the next few weeks will not be doing so out of archaic bigotry. That regrettable aspect of Orangeism has been in decline for decades, along with the Orange Order's political influence within the Unionist party. If there had been a durable, honourable peace, the Orange movement would gradually have declined into little more than a folk festival: as harmless as Morris dancing. As it is, Orangeism has had no difficulty in recruiting new support and eager marchers, from the many Unionists who believe that they have been lied to and fear that they are being betrayed.

Nor are they exaggerating. When they signed the Good Friday agreement, the Unionists made two remarkable concessions. They agreed to the early release of terrorist murderers. They also agreed to sit down in government with men who had spent decades organising terrorism and murder; men who, had they been Serbs, would have been liable to be seized and taken to The Hague for trial. It was not easy for Unionists to agree to all this, yet they did so, in order to secure peace.

To obtain their community's support for these terms, however, the Unionist leadership insisted on going into detail. The Unionists received handwritten assurances from Mr Blair as to what he intended peace to mean. He made clear that the various paramilitary organisations would not merely be required to disarm. They would have to cease training and recruiting and dismantle their structures – in effect, abolish themselves. On that basis, the Unionists signed the deal which enabled amnestied terrorists to become ministers. Without those prime ministerial assurances, no deal might have been signed.

Tony Blair's definition of peace was eloquent and at the time, seemed sincere. Since then, it has been systematically violated. IRA decommissioning has been minimal, more than outweighed by new arms purchases. Intelligence reports suggest that the Provos are at least as well armed as they were four years ago. They are also recruiting, training and drilling without interference. Nor is anyone trying to prevent the IRA from strengthening its hold on its own areas: a hold based on racketeering and intimidation. The Prime Minister has done nothing to prevent his ministers and officials from breaking his word.

They have replaced it with a new definition of a ceasefire: a paramilitary one. The paramilitaries are allowed to do almost anything they like – even the occasional murder – without forfeiting their political rights, as long as they do not murder policemen or soldiers.

This is not peace; it is only a temporary absence of hostilities. When the Unionists signed the Good Friday agreement, they assumed that they were working towards the restoration of the rule of law, with no more no-go areas and no more paramilitary ghettos. They have now discovered that the British Government is content with a kind of mafioso stand-off.

The Unionists have found it easier to arouse indignation about all this in Washington than in London. Because the IRA is under no pressure in its domestic strongholds, it has been able to expand its international activities, especially in Colombia and in the Middle East. The revelations about the Provos' Colombian involvement – drug-trading and terrorism – angered the Americans, who would have been happy to co-operate with any punitive measures which the British Government had suggested. But none were made. What aroused outrage in Washington caused mere embarrassment in London.

The same was true more recently, over the gross breach of security at Castlereagh, where the IRA gained access to vital Special Branch files. Yet again, no political repercussions followed. It was as if the Government was sending the Provos a signal: "Whatever you do, please try harder not to be caught. It's so awkward for us when you are."

The Unionists certainly believe that this is the position. They note the contrast between the Provisional IRA, able to serve in government while retaining all its terrorist capability, and the Royal Ulster Constabulary, weakened and dishonoured by the Patten reforms. It may not do them any good to express their feelings by joining Orange marches, but Unionists can hardly be blamed for finding some peaceful means of registering a protest – even at Drumcree.

The Orange march to Drumcree church has been taking place for nearly 200 years. It's route includes the Garvaghy Road, which may be a predominantly Roman Catholic area but it is also a main route into Portadown. London is a predominantly heterosexual city, yet Gay Pride demonstrators are allowed to process along its thoroughfares. Orangemen should be equally entitled to hold their marches on the thoroughfares of Portadown.

The Orangemen's anger is also aroused by the nature of the opposition they face, from so-called local residents' committees. At Drumcree and elsewhere these are dominated by Sinn Fein and used by it as a means of extending control over Catholic council estates. In the case of Drumcree, one of the prominent "residents" had been convicted of blowing up a British Legion hall. The Orangemen can hardly be blamed for questioning his right to determine their rights to freedom of assembly.

Nor is Drumcree an isolated event. It would not receive the attention it does unless it were symptomatic of a wider Unionist discontent. Encouraged by Tony Blair, David Trimble succeeded in persuading a majority of Unionists that it was in their interests to accept the Good Friday agreement, despite its many unpalatable aspects. Four years later, let down by Tony Blair, Mr Trimble is finding it harder and harder to keep Unionism in line. An increasing number of Unionists are not prepared to tolerate permanent paramilitary control over significant areas of Belfast and other cities.

They do not regard that as peace, and who can say that they are wrong? The peace of God may pass all understanding. The same licence should not be extended to a peace deal negotiated by Mr Blair.