ON the historic day of peace, the headlines from the Dublin and Belfast newspapers spoke in a unison of celebration: ''Yes And Yes, It's The People's Agreement'' acclaimed the Sunday Independent (the Republic's largest circulating Sunday). ''People's Verdict: 71% Vote Yes'' agreed the Belfast tabloid, Sunday Life, emblazoning the figure in dynamic red against black.

The affirmation rang round other titles. ''Yes'' chorused the liberal Dublin-published Sunday Tribune. ''Yes, Yes, Yes,'' rejoined Belfast's Irish News, a pro-nationalist daily which published a special Sunday edition. The News Letter, a pro-unionist publication which also published a special Sunday edition, had campaigned vigorously for a ''Yes'' vote and celebrated with a note of vindication: ''676,966 People Can't Be Wrong . . . Well Done Ulster.''

The dual-edition Dublin and Belfast tabloid Sunday World carried the upbeat: ''The War Is Over''. Ireland On Sunday, the newest title to offer north and south circulation, hailed a ''Landslide! Country Stands United''.

Only the pro-Sinn Fein Sunday Business Post sounded a negative note in its Dublin edition: ''Yes Vote Triggers Arms Row'', a case of anticipating the next hurdle rather than standing still to savour the victory.

Its editorial predicted the ''liquidation of the paramilitary arsenals'' if the Republican leadership was spared the indignity of having to formally surrender arms.

In the Sunday Tribune, Ed Moloney also predicted that while David Trimble and Tony Blair would be under pressure to deliver on decommissioning, it would only happen if it was ''seen to be a voluntary move by the IRA''.

Mr Trimble's achievement in delivering a Unionist majority vote for Yes earned him a new respect in the Dublin editorials and columns.

The Sunday Independent editorial called him ''a figure of great moral courage and shrewd political judgment, one who has been ready to meet the challenge of agreeing an inclusive political settlement''.

Little magnanimity, however, even in victory, could be extended to the ''dinosaur'', Ian Paisley. ''A Lear minus the mad king's finer qualities,'' wrote John Drennan in the Sunday Independent.

The Sunday Tribune, though, warned that the scale of this weekend's victory would ensure that the Noes would return to the ballot box in force and might have a ''disproportionate impact''.

Even in the moment of a historic vote, which has surely transformed the face of Irish politics forever, the phantoms of decommissioning and the dinosaurs are glimpsed nervously. In Ireland, the dragon must be slain at least twice.