Why did they do it?

With this latest bombing, the IRA seems to have turned its back on the peace talks. Perhaps it has given up on John Major

There were times, during the 1970s and 1980s, when incidents such as yesterday's horror in Manchester were actually quite popular among many of those who live in Belfast's republican ghettos.

In those days the feeling was widespread among republicans that such bombs gave the British a salutary taste of the Northern Ireland war, and demonstrated that the conflict was not confined to the island of Ireland.

But yesterday, when news of the bombing came through, it took only a few phone calls to people living in west Belfast to establish that many republican sympathisers were experiencing the same sick, sinking feelings in their stomach as non-republicans.

This time there was little trace of the old grim satisfaction of a blow being struck against Britain. Instead, it was summed up by one man who said, "Oh, Christ no, not again." This change in sentiment will serve as little consolation to those in Manchester whose faces were flayed by flying glass. But it will provide some hope to those who fear that another 25-year cycle of death and destruction is in the making.

The bombing showed, yet again, that the republican movement in general and the IRA in particular is a completely unpredictable entity. In recent weeks there had been the usual range of reports and speculation about their intentions. Some predicted that a ceasefire could happen in advance of the talks that opened in Belfast on Monday; many hoped another cessation was possible within weeks or months, if the IRA became convinced those talks were for real. Only a few thought such an attack was on the cards.

Most considered an attack conceivable but improbable, going as it does against the flow of opinion within the republican movement generally. One huge unanswered question is whether this is the start of another sustained IRA campaign in Britain or simply one of an occasional series designed as cruel reminders that the IRA, though inactive in Northern Ireland, has not gone away.

What the bomb certainly does signify is that a struggle is going on for the heart of the republican movement. The IRA army council, which must have ordered the attack, has military control over the gunmen, the bombers and their supplies.

It appears to contain military purists, impatient with the peace process which has dominated Ireland in recent years and happier with the old simplicities of fertiliser and Semtex. They literally call the shots: IRA volunteers are subject to their discipline and must carry out their orders. Failure to do so, it is widely understood, may result in death.

One of the old certainties was that the army council was in charge of everything. Its word was law: volunteers did what they were told and Sinn Fein, which in the old days was merely a useful propaganda accessory to the IRA, responded to its directions.

But on both fronts things have changed. The military discipline was thrown into question when, earlier this month, armed raiders shot dead a detective in Limerick. This sent a shock-wave through the Irish Republic whose largely unarmed police force, the Garda Siochana, enjoys an extraordinarily high level of public support.

The IRA said at first that none of its members had carried out the killing, a statement which was taken seriously by the Dublin government and others, since such IRA denials have in the past proved reasonably reliable. But it soon became obvious that an IRA unit in the west of Ireland was indeed involved.

Only yesterday the IRA issued a second statement, now admitting its members were responsible but denying the killing had been authorised. No one is quite sure what this means. The murder could have been a direct challenge to the IRA leadership, or a raid that went wrong; it could have represented an outright rejection of the whole philosophy of the peace process. Either way, it left a police officer dead and introduced serious doubts about what is happening within the IRA.

Now the Manchester bombing has posed the most fundamental of questions about the state of opinion within the republican movement. The army council is formally in charge, but there are increasing signs that the movement at large is looking for leadership not to the IRA but to Gerry Adams and the others who lead Sinn Fein.

The August 1994 ceasefire was, as one republican put it, "the most popular thing we ever did in 25 years". It came as a result of a complex process of which Mr Adams and his associates were among the principal architects. They built up Sinn Fein into a party which last month attracted 40 per cent of the Northern Ireland nationalist vote.

They established a modernised concept of republicanism with a new vocabulary, in which victory took second place to peace. And, crucially, they constructed a plausible alternative to the campaign of terrorism, in which Sinn Fein would wield influence by forging new links with constitutional nationalists in Ireland, north and south, and in the United States.

The record vote won by Sinn Fein in last month's election was viewed in Belfast as a comprehensive endorsement of the peace process approach. That endorsement came both from traditional republican voters and from a host of new supporters who cast their votes tactically in support of Mr Adams and of a renewed peace process.

The Arndale Centre bombing therefore flies in the face of that overwhelming support for negotiation in preference to violence. The Sinn Fein vote was seen as strengthening Mr Adams's hand greatly in the internal debates within the movement and seemed to increase the chances of another ceasefire. Northern Ireland tasted peace during the last ceasefire, and liked it. Few if any new jobs came to the ghettos, but the quality of life improved dramatically, if only because the chances of attack from extreme loyalists, and of street friction with the security forces, faded away.

Besides, the theory, propounded by Mr Adams, that the British and the Unionists were not to be defeated militarily, but were more likely to be outmanoeuvred by a broad nationalist coalition, took firm root in the ghettos. But while Mr Adams decisively won the wider debate, he seems to have lost the argument with the army council.

The signs are that Sinn Fein's leaders want to be in talks and in the political processes. They will not admit it publicly, but they are likely to be dismayed by the Manchester attack. Like their voters, they have come to believe that such acts of violence are counter-productive.

The differences between Sinn Fein and the army council are so enormous that in any other organisation they would have produced a split. Sinn Fein wants to win friends and influence people, while IRA bombs produce only isolation, at home and abroad. But republicans are determined that there will be no formal split and so they stay together, even though in reality there is a yawning gap.

Bombs will clearly keep Sinn Fein out of the talks that opened in Belfast this week. Furthermore, they will certainly endanger lives in Northern Ireland, for while the IRA may have no intention of resuming its campaign in Belfast, there have been signs of restlessness within the extreme loyalist groups.

Those groups specifically warned in March that further IRA attacks in Britain carried the risk of loyalist retaliation. A statement warned then: "These atrocities cannot be permitted to continue without a telling response. We are poised and ready to strike to effect. We will give blow for blow." A new eruption of loyalist violence could bring IRA retaliation in Belfast, thus starting a new cycle of violence.

All this is obvious to the IRA, to Adams, and to almost everyone in Belfast: it is a scenario that sketches out how a city whose people do not want war could yet be plunged into further conflict.

The gulf between the Adams approach and the actions of the IRA is clearly very wide, yet there is one point of agreement between them. A number of leading Sinn Fein people have said publicly that the present British government is too dependent on Unionist goodwill in the Commons lobbies to enter into serious negotiations with republicans.

The IRA must believe this too, for with this latest bomb it all but rules out Sinn Fein entry into the present negotiations. The larger question is whether the bomb means the IRA is writing off the Major government, or putting paid to the entire peace process.

In 1994 the IRA made an important and potentially historic shift by declaring a ceasefire in order to facilitate talks. In doing so it abandoned the old, impossible, position that it would stop bombing only when a united Ireland was on the way. Perhaps its leaders believe that the peace process can be revived next year, when they would hope to do business with a new, stronger British government; or perhaps they are regressing towards that former position.

The first scenario would mean that the peace process could yet again be resurrected, as it has been after so many apparently fatal blows. The second scenario would mean that a streak of near-nihilism is prevailing over the wishes of the republican community as a whole, and that the bleak prospect of more such bombings lies ahead.