The answer to an Irish victory over France tomorrow lies in the unlikely vaults of the history of World War Two. In the European campaign, General George S Patton had a picture of his opponent Erwin Rommel pinned on the wall of his caravan.
He also read everything written by the German on warfare, the better to understand him. It is unlikely that Declan Kidney has paid much attention to the mental make-up of Marc Lievremont in the build-up to the game at the Aviva Stadium.
Lievremont is the key to beating France. Ireland must concentrate on winning the psychological battle, which will dictate the tactical plan. Neither plan will work unless they set a physical challenge for Les Bleus. Ireland face a huge problem.
The French are simply better in 12 of the 15 positions. Only Brian O'Driscoll, Jonny Sexton and Paul O'Connell are good enough to be certain choices for their opponents.
Yet it has always been thus and the victories of the past were invariably based on discomfiting the French early on. Who can forget the three-pronged attack by the Munster pack on Sebastien Chabal at the kick-off against Sale in Thomond Park?
Patton had it right, "de l'audace, encore de l'audace, et toujours de l'audace". Audacity, more audacity, and ever more audacity.
In 18 months in charge, the French coach has used over 80 players. Last November, his team caved in against Australia and conceded 59 points. Just three months later that was turned around, and they put 34 points past Scotland, albeit while conceding three tries.
Which match represents France? As always the answer lies somewhere in the middle, but the heart of this team is nowhere as strong as that which beats between the green shirts of every one of Kidney's men.
Andy Robinson had a plan akin to Patton. He kept attacking even when under pressure. His team were not good enough, but they pointed the way for Ireland.
The All Blacks with the same possession and counter-attacking skills would have beaten the Scots by 60 points and not conceded a try.
Last week pointed to a vulnerability in the French side that Lievremont has inculcated by his tinkering with selection. For over a 100 years Ireland's strength has been their continuity of selection which has led to the old virtues of team spirit, confidence and pride.
Kidney and O'Driscoll gave an astonishing pre-match interview in Rome in which they did nothing but talk about the possibility of defeat on the morrow and the strengths of Italian teams in the Magners League. I believe that fear was communicated to the team and resulted in the performance.
This week the captain has continued the negative vibes. "If we make mistakes like last week, we will be destroyed," he declared in a newspaper interview. Micheal Martin's scriptwriter should be employed immediately to write some positive words for the Irish management.
The Fianna Fail leader is in a hole and yet speaks like he is De Valera. Kidney and O'Driscoll, barely 24 months after the heroics of a Grand Slam, sound like Brian Lenihan on a bad day at the IMF.
The Irish captain was right in saying that mistakes will be punished by France. The answer is not therefore to follow the Scottish plan, which gave the opposition far too many chances to counter-attack.
Instead, Sexton must borrow from the Ronan O'Gara playbook and kick for position and, especially, put the ball in the air. Clement Poitrenaud must be forced to make the catch outside the '22' and the chase by Ireland must be fast and furious.
At the bottom of the ruck, the dark arts should be practised and the French full-back should hear the phrase"welcome to Dublin" whispered in his ear, preferably in his own tongue.
Counter-attack can only be practised if the ball is coughed up in attack or kicked straight to a defender. For over a decade O'Gara forced French defenders to turn; Sexton must do no less.
The plan to beat France should be simple: kick it in the air and let God judge it; make it a match of line-outs where we can compete rather than scrums where we cannot; let us not match flair with flair but rather with courage.
The Aviva has yet to sound like the old stadium it replaced simply because Irish supporters have not been given a reason to raise their voices in exultant support for their country.
It would be a start if in the warm-up Jamie Heaslip worked the crowd rather than practised drop-goals for his admiring fans. I will travel in hope rather than expectation because I suspect Kidney never read Patton.