James Lawton: Ireland's survival instincts must be invoked in bid to sabotage French
If Martin O'Neill had another life, he has sometimes mused, it might be as a forensic examiner of serious crime, a prosecuting lawyer fascinated by the challenge of probing the darker side of human nature.
This being so it is hardly surprising that in the last few days, and from the moment he knew his team would meet France in Lyon tomorrow, he has found himself weighing all over again that incident which any Irish football fan might reasonably described as the crime of the 21st century.
Of course - and like so many of the most amiable followers in all of international football and at least some of his players - he has been conjuring again the appalling moment Thierry Henry betrayed his almost mystical reputation as a player beautifully attuned to all in the game that was fine and subtle and uplifting.
Who can forget Henry's ugly descent into a piece of street mugging, a blatant handball which he disguised so well from a referee who would be haunted for the rest of his career by the scale of the hoodwinking?
Henry's swift transfer of the ball to the goalscorer, William Gallas, the commiseration he offered a distraught Richard Dunne, as they sat together on the field after the final whistle, can never be separated from the fact that Ireland were denied a fair chance of competing in the 2010 World Cup finals in South Africa.
That is an injustice you do not flick away like a speck of dust on your lapel. You do not have to nurse along the angst. It is the kind that can spring back at you from a clear blue sky.
The FAI, of course, accepted five million-plus worth of hush money to go away and if the Irish players and fans were the outraged victims, the watching Arsene Wenger saved his greatest sympathy for the deceived referee?
"I feel so sorry for him," said Wenger, "because he was the only person in the world didn't see what happened."
Seven years on, the bible of French sport, 'L'Equipe', admits, "There here is a score to settle".
No doubt, but is it folly for the team which so brilliantly concentrated on the task of beating Italy last Wednesday night, to immerse themselves in old emotion and, maybe, a distracting lust for some atonement?
O'Neill, plainly, is not sure. A little bit of warmed-up righteous indignation, might serve some purpose, perhaps,
But, then, it could also separate his players from the basic imperatives of covering the ground and applying the pressure that eventually saw off the Italians who went into the game believing that, even with eight changes, they would still be too slick, too sophisticated to lose the unbeaten record so impressively created against Belgium and Sweden.
"I'm not surprised Henry doesn't like talking about it," said O'Neill this week.
"It was a serious breach; it might be a jocular thing to talk about now, but it wasn't at the time.
"It was deadly serious and of course it will come up in discussion over the next day or two, although though I'm not sure I will use it as some kind of incendiary force.
"I wasn't aware it was such a big issue in France but when you think about it why shouldn't they feel guilty. I think it is a bigger deal for the French than it is for us. No doubt about it, Thierry Henry is still causing controversy all these years on."
Yet even if the Irish supporters, the joyful heirs of those who cooled themselves in the fountains of Rome in 1990 and so happily greeted the dawn on New York's Third Avenue four years later, have been embraced by their French hosts as the least rancorous, and most friendly, of all their visitors, the more worldly of them will see the potential for the most spectacular righting of a grievous wrong.
Imagine the scale of the implosion of Euro 2016 if, somehow, the Irish were to ambush Didier Deschamps' side with the kind of resolution which brought such agitation to the coach of the moment, Italy's Antonio Conte?
Eighteen years ago France's World Cup final victory over Brazil turned the Champs-Elysees into the epicentre of an ecstatic and hugely relieved nation.
The release came from the fact that the French team, like this one, had been targeted by some of the more virulent sections of the right wing.
It said that the character of the national team had been diluted; there were too many players - Lilian Thuram, Marcel Desailly, the young Henry and Patrick Vieira and the eventual superstar Zinedine Zidane - with roots in the old French colonies.
Now there are charges that today's team has been purged of players with Muslim antecedents.
However, like the 1998 team, today's has the chance to dispatch such clouds.
The young, brilliant Paul Pogba might yet reach out for the mantle of the player of the tournament. Dimitri Payet, from the island of Reunion in the Indian Ocean, is already halfway to entrancing the nation with his superb running skills and exquisite finishing.
So how best do Ireland try to wreck the fete along Champs-Elysees?
O'Neill says that the imperative is not some hot pursuit of revenge for an old crime but a cool understanding of how it is they have survived for the challenge in Lyon.
They have to recall how they stunned the reigning world champions Germany in the qualifying action, how they wore down the Italians who had been charged by their coach with the job of maintaining the momentum of a brilliant start to the tournament.
None of this may be enough to sabotage the French, but it is the model which gives Ireland their best chance of a worthy challenge in one of the great football occasions of their lives.