The News From Northern Ireland

IN old joke in Irish politics posits that the first thing to discuss at any political meeting is ''the split.'' If Gerry Adams's Sinn Fein has managed to get the Irish Republican Army to halt its violence without a split, then it has achieved something momentous.

But why now? Why, after 25 years, after more than 3,100 deaths, after countless stories of personal tragedy, after billions of dollars worth of economic damage, has the IRA decided to hang up its Armalites?

First, it is possible, as the loyalists and unionists fear, that the British have given some secret concessions to the nationalist Sinn Fein and the IRA. But this seems unlikely. The British government had little to offer. The IRA's main demand is for a united Ireland. It is hard to see how the British government could deliver such a thing, even if it wanted to. London has long agreed that Ulster will remain part of the United Kingdom for as long as the majority of people in Northern Ireland want it to. Fu rthermore, the current border has been agreed upon as part of European Union legislation.

Other conceivable concessions are not really concessions, but the natural consequence of the end of terrorism. Reduced security (the British Army off the streets) and leniency toward jailed activists would be welcomed equally by loyalists, who have just as many young men behind bars. Other demands -- civil rights, equality, non-discrimination and so on -- were met, legislatively, as long ago as 1970.

A second, more likely reason for the sudden abandonment of arms is that it isn't sudden at all; rather, it is the culmination of many years' work by the new leadership of Sinn Fein to turn the republican movement into a wholly political movement. The movement last split over the issue of whether it would take seats in, and thus recognize, the Parliament in Dublin. Diehards opted for guns and bombs. Those remaining, the majority, have been slowly guided by Mr. Adams and others toward political activism and away from violence.

If this second possibility is the reason, then it is to be applauded. It is a risky strategy for the people who have brought it about. Historically, it has been almost impossible for the political wing of the movement to dissuade the armed wing from violence on a long-term basis. Sadly, republicans who have turned to political methods have met with little success or support.

Sinn Fein, due to its links to the IRA, enjoys vast amounts of publicity, but it enjoys scant political support. In the last census in Northern Ireland, as many people identified themselves as having ''no religion'' as identified themselves as Sinn Fein voters. In other words, not many. Yet Sinn Fein, 9 percent of the population of Northern Ireland, talks as if it is the only political party that matters, a claim difficult to make without an active IRA.

Lastly, in recent years the IRA's attacks have been met by bombs and bullets from its Protestant opponents, the Ulster Volunteer Force (UVF) and the Ulster Freedom Fighters (UFF). These loyalist gunmen saw that IRA explosives led to valuable concessions in the Anglo-Irish Agreement of 1987. They concluded that violence works. Now, in 1994, they are murdering twice as many people as the IRA and in such a haphazard way that no Catholic or even assumed Catholic has been safe from their bullets. They killed se veral of their own people who happened to be in the wrong place.

Since the IRA cease-fire, the UFF has killed again. In the past the IRA itself proved that no amount of military presence can stop terrorism. Now, while the security forces have been increasingly successful against the UVF and UFF (prisons are overflowing with their members at the moment), they have been unable to stop the campaign of Protestant terror in the Catholic communities. The only hope for a cessation of the random killings by the UFF was for the IRA to stop its own war. Which is a way of saying t hat violence begets violence. The question is whether both sides have learned this lesson.

If the peace holds, the politics that follow will be acrimonious and spectacular, but at least no one will get hurt. And the people of Northern Ireland will enjoy the luxury of thinking about other things for a change.