Thursday’s meeting between Sinn Fein leader Gerry Adams and Prime Minister Tony Blair led to nothing of substance — no peace plan, no agreement on reunification, no accord on amnesty. All it produced was the one thing Northern Ireland needs at this moment above all else — hope.

The meeting at 10 Downing Street was short, just an hour. Adams and Blair shook hands, sipped tea, expressed their mutual desire for peace, agreed to keep talking and parted. No monumental breakthrough, not even a doorstep grip-and-grin photo for the press.

But still a vast improvement over the scene there six years ago when an IRA mortar round fell into No. 10’s garden, blowing the windows out, nearly killing then-PM John Major. And an incalculable improvement over the 30 years of violence that has taken more than 3,200 lives.

The last time a republican leader set foot in that legendary address was in 1921, 76 years ago, when Michael Collins and Lloyd George signed the treaty that gave independence to 26 Irish counties but left six, Northern Ireland, under British rule. For his attempt to end centuries of strife, Collins paid with his life, murdered by nationalists.

The two who met Thursday are taking a similar risk. Adams is under attack from two sides: Unionists claim Sinn Fein is merely a front, an attempt to legitimize IRA terrorism; extreme republicans see any negotiations as a sell-out. Blair also walks a tightrope — appeaser or imperialist. One false step could cost both men their political or actual lives. The current cease fire is fragile, the lunatic fringes on both sides are no strangers to violence.

The central point, of course, is whether the two Irelands will be reunited. But before the crux comes a host of peripheral issues that easily could smother this peace process in its infancy: IRA insistence on a new investigation into the 25-year-old Bloody Sunday massacre; amnesty for convicted murderers of Orange or Green hue; the extent to which republicans and unionists want one last round of retribution for past wrongs.

Predictably, this ray of hope immediately was denounced by those who see a future in revenge. Ian Paisley, the unionist leader whose very career depends upon continued strife, called the meeting “an exercise of outrageous hypocrisy and deliberate lying.”

Then there was Rita Restorik, the mother of the last British soldier killed by the IRA, who approached Adams after the meeting with a Christmas card and these words: “Put an end to these horrible killings. I want no other mother to go through the pain I suffered.”

There are many voices in this debate. Whether Thursday’s meeting proves to be a historic event or an irrelevant footnote depends greatly upon which the people of Great Britain heed.