Northern Ireland’s peace process faces its gravest crisis since George Mitchell negotiated the Good Friday accord–graver even than after last summer’s bombing in Omagh by a small band of breakaway republicans. This time, it’s not marginals but the mainstream of Protestant unionist leadership who have thrown the process into jeopardy, and with it the resolution of Europe’s longest-running civil rights struggle and civil war.

The Good Friday accords called for Northern Ireland self-government with Catholic-Protestant power-sharing. Disarmament by the IRA and Protestant loyalist paramilitaries was to move forward on an independent track. But unionist leader David Trimble, fending off militant unionist challenges to his leadership and abetted by dodgy language from British Prime Minister Tony Blair, began insisting that the IRA disarm before its Sinn Fein allies could take their elected seats. By the June 30 deadline for forming the new governing body, Trimble had painted himself into a corner.

The real culprit is a unionist political vocabulary built since the turn of the century on the slogan “Ulster Says No.” To the unionist siege mentality–of people who command a political majority and make up 93 percent of the police but whose power is eroding with Catholic population growth–every compromise by Gerry Adams and Sinn Fein is, in Trimble’s words, a “con job.”

Yet by the end of June Sinn Fein had made an extraordinary commitment to “persuading those with arms to decommission them in accordance with the Agreement.” And the IRA itself has sustained its cease-fire in the face of escalating attacks by loyalist paramilitaries, who have staged at least forty-five pipe-bombings against Catholics since January, as well as the bombing murders of civil rights lawyer Rosemary Nelson and Elizabeth O’Neill, a Protestant married to a Catholic.

When the deadline passed, Blair and Irish Prime Minister Bertie Ahern went public with a dramatic proposal to begin disarmament shortly after the new government’s inauguration on July 15. They hope that a silent majority of Protestants eager for settlement will lure unionist leaders from their rejectionist corner. The Clinton Administration is dangling carrots and raising sticks to preserve its one unalloyed foreign policy triumph, with the President himself lobbying Adams and Trimble.

The best hope lies not with political brinkmanship at Stormont Castle but with shifts in both Catholic and Protestant public consciousness aided by meticulously balanced historical reckonings. In the run-up to June’s negotiations, a British tribunal reopened an investigation into Bloody Sunday, the 1972 killing of fourteen Catholics by soldiers. A former Royal Ulster Constabulary informant was charged with the 1989 murder of civil rights lawyer Pat Finucane. Loyalist and republican paramilitary prisoners walked free. The IRA released information about those “disappeared” during the seventies. It’s as if each historic grievance is an obstacle to be overcome so that negotiations can occur on the terrain of the present.

If the new deal succeeds, the power-sharing executive it creates will not alone bring justice to Northern Ireland. As Bernadette Devlin McAliskey warns, it will not bring the united Ireland sought by republicans but an “agreed Ireland” with battles of equity and inclusion still to be fought. Nor will “decommissioning” guarantee peace; the decommissioning debate is about who’s a terrorist and political legitimacy. The real guarantor is a distribution of power that all sides find equitable. That can happen only if David Trimble and the unionist community take a leap of faith and consign “Ulster Says No” to history.