The murders of two British soldiers and a policeman in Northern Ireland by two splinter groups of dissident republicans have reawakened fears of a return to brutal sectarian war.
The good news - at a time when there is little to be found worldwide - is that Northern Ireland's Catholic and Protestant leaders stood up together and denounced the killers as a discredited vestige of the past.
A decade after the 1998 Good Friday agreement set the province on the road to power-sharing, a tortuous process that has made exceptional progress since 2007, the efforts of spoilers to shatter that progress must be stopped.
The dramatic shift that has taken place in the last 10 years was reflected in the words of Martin McGuinness, former Irish Republican Army commander and leader of the IRA's political wing, Sinn Fein, who is now deputy first minister of Northern Ireland's provisional government. McGuinness called the killers "traitors to the island of Ireland. They have betrayed the political desires, hopes, and aspirations of all of the people who live on this island."
McGuinness was echoed by his Protestant counterpart Peter Robinson, first minister of the power-sharing government and leader of the largest Protestant party, who said: "This is a battle of wills between the political class and the evil gunmen - and the political class will win."
Their comments seemed light-years away from the days when relations between the sects were marked by bombs and bullets. So did the outpouring of Catholics and Protestants at joint vigils and the funeral of the slain policeman.
The militants appear intent on restoring the era of The Troubles by undoing recent progress on police reform that has the support of Sinn Fein. They have carried out scores of nonfatal attacks on police in the last 18 months, and probably hope they can provoke the British into sending its army back to patrol the streets of Northern Ireland. This would sour Catholics on the power-sharing accord.
What was most stunning about the mainstream republicans' response to the crisis was Sinn Fein leader Gerry Adam's call for party supporters to help police find the assassins. This breaks a longstanding republican taboo against informing; it demonstrates the republican commitment to pursue a united Ireland through politics, not bullets. It is hoped that all Protestant leaders will counsel their former militants against retaliation to the killings.
When McGuinness and Robinson visit the White House tomorrow on St. Patrick's Day, they should be saluted for showing that sectarian wars can be channeled toward a peaceful resolution. They deserve all possible help in ensuring that the political class trumps those who won't give up their guns.