Too often in US Irish bars, second-, third- and fourth-generation Irish Americans are heard to express views that betray a profound ignorance of the "olde countree" and its modern history. By condemning the bomb in Co Tyrone, Sinn Fein has reached an audience that no amount of peaceful words from heads of state or moderate political leaders previously could. .
A sense of the significance of this moment should not, however, be mistaken for dewy-eyedness. To appreciate the distance Sinn Fein has travelled over the past couple of years is not the same thing as to embrace them as brothers or even to regard them as trustworthy.
A case in point was Martin McGuinness's appearance on Newsnight on Tuesday, when he suggested that he knew no more about the Omagh bombers than Kirsty Wark, the interviewer. If you took this at face value, Ms Wark would surely have a case for defamation.
But the pleasing prodigality of Sinn Fein at the moment is no more than a beginning in the embracing of democratic norms. One of the more interesting aspects of the explosion on Saturday is that the appalling violence by a group of people calling themselves the "Real IRA" reminded us that the other IRA has perpetrated similar atrocities.
A strong gesture is needed now from the Sinn Fein republicans: an almighty shove to set the ball rolling again. There are several things they could do. While there has been historical resistance within the republican movement to "informing" on ex-colleagues (all manner of vicious punishments have been doled out to snitches in the recent past), passing information about renegade IRA members to other participants in the peace process is not the same thing. Sinn Fein should encourage their members to help the security services.
It's entirely possible, of course, that this has already happened: there would be no obvious advantage for Sinn Fein in admitting it. But it would have the advantage of reducing the extent to which the IRA and Sinn Fein are hostages to their own past. As such, it would be a measure of how serious they are about the future.
Decommissioning weapons is the other big opportunity. To start handing over guns and explosives would be both useful and symbolically important. Useful because, although knowledge about how to get hold of guns in the first place is more valuable to guerrilla organisations than the guns themselves, any reduction in the weaponry scattered around the fields and barns of Ireland would translate to a reduction in the danger of opportunistic violence from groups not involved in the peace process. Guns destabilise; that is what they're for.
And it would be symbolic because, after refusing to accept the legitimacy of the RUC or the weapons of the British Army for so long, to decommission even a proportion of the IRA's armoury would be to take a gigantic step towards a final agreement in which the monopoly on legitimate violence would be held by the state in the eyes even of republicans. That's why complete decommissioning is the IRA's final and trump card. To see them play it would be a real pleasure.Reuse content