FESTERING divisions within the Irish Republican Army may be pushed into an outright split between a group that still seeks peace, and another faction determined to resume its armed struggle to rid Northern Ireland of British rule.
The danger of a breach opening up in the IRA, with the possibility of violence returning to mainland Britain, has been constant since the cease-fire began in September 1994. But, faced with delays in peace talks, some fear the danger may be imminent.
Prominent among them is former US Sen. George Mitchell of Maine, who headed a three-man international commission on disarming the IRA and who warned of a possible split on British television Sunday.
His warning came after British Prime Minister John Major proposed holding elections in Northern Ireland late last month and delaying all-party peace talks. Major's proposal sidelined the international commission's recommendations, raising sharp criticism among Catholics and sharpening divisions in the IRA.
Senator Mitchell is not alone in his concern. The scenario of a renegade IRA group initiating its own campaign of violence had been given close scrutiny by Northern Ireland security forces several days before Mitchell issued his warning, British government sources say.
A renegade faction of the IRA may have fewer than 100 members, and would lack public support among Northern Ireland's citizens, who almost universally support the cease-fire. Fear of an IRA split is part of the reason Catholics in Northern Ireland do not want to wait for elections to keep the peace process moving. But Catholics at the same time are also uneasy about elections because they would manifest the population differences in the province, giving Protestants a majority representation in the elected body.
Mitchell spoke amid growing concern that mutual recrimination between London and Dublin and in Northern Ireland was poisoning the peace.
Dublin's resistance to Britain's latest policy has not faded. ''One of the great difficulties that divides Dublin and London at the moment springs directly from the fact that there are fundamental differences between the concept of negotiation and the concept of elections,'' said Irish Deputy Prime Minister Dick Spring this weekend.
A feature of developments since release of the Mitchell report has been visits to Washington by senior players in the peace process.
Gerry Adams, president of Sinn Fein, the IRA's political wing, met President Clinton last week during a session with national security adviser Anthony Lake. Mr. Adams has since denied that Mr. Clinton urged him to accept elections. The White House has remained studiously neutral.
A senior British adviser said: ''Adams is a moderate, relatively speaking, but there have to be doubts about his ability to keep the lid on tearaways in IRA ranks.''
Late last week, in one of the worst breaches of the cease-fire, a gang attacked the home of a policeman in County Tyrone, firing 57 bullets. British security authorities blamed the IRA for the attack in which no one was injured, but the IRA denied responsibility.
Britain wants the IRA to decommission its weapons before all-party talks largely because of its concern that an armed breakaway element in the movement could either destroy the cease-fire at a moment of its own choosing or put military pressure on those engaged in the political process. Although complete decommissioning would be impossible to guarantee, partially giving up its arms would indicate a political commitment against violence by the IRA.
A further sign of the fragility of the cease-fire came on Jan. 30 with the murder of Gino Gallagher, chief of staff of the Irish National Liberation Army (INLA), a republican group more radical than the IRA. The INLA has never publicly accepted the cease-fire, but Northern Ireland police appear to discount that it was responsible for the County Tyrone attack.
Mitchell accompanied his warning of an unraveling of the cease-fire with a call for ''peace negotiations to begin as soon as possible.''