Way before the season began, Marc Lievremont and Declan Kidney would have highlighted tomorrrow's clash as the pivotal game in their calendars.
For both, the ultimate goal is the World Cup in September, but this Six Nations is also hugely important to the two of them.
Win today and it's full speed ahead; lose and it's catch-up from the off.
France hit the ground running in the opening round. They weren't just good against the much-improved Scots, they were very, very good. A week on and with confidence high, they should be even better at the magnificent new home of Irish rugby.
Ireland, by contrast, were pushed to the limit in Rome in a game that has become tinged with arrogance.
For us, the annual joust with the Italians has become lose/lose, however we approach it. Win and it was expected and, unless we manage a bucketful of tries, the individual and collective performance will be slated in the aftermath.
It's easy to start thinking like that. We didn't play well in Rome, but we did win. We made an uncharacteristically high number of unforced errors, not least through Gordon D'Arcy and Brian O'Driscoll. A repeat of the same tomorrow and we will be carved to pieces on the scoreboard.
And please, for once, may we be spared this fairytale fantasy about the French being 'bad travellers.' It is a myth straight out of the best of Hans Christian Andersen stories. The facts most certainly do not back it up.
For the record, we have taken the spoils in this Dublin fixture just four times in the last 35 years, while they have emerged victorious 11 times in that same period. Would that not suggest that it is we who have the difficulty travelling -- when shifting from hotel to ground!
Oh, and for what it's worth we have won just once in Paris in the past 40 years!
Every team in every code prefers, for obvious reasons, playing at home and, to that end, the advantage is with us tomorrow afternoon, but to suggest the French struggle on the road is disingenuous in the extreme. The facts certainly don't stack up when it comes to Dublin.
And this time round, they travel stronger through enforced change than they lined out in Paris eight days ago. Injury to Maxime Mermoz against the Scots sees Damien Traille restored to his best -- and in my view only -- position of inside-centre, making for a formidable combination alongside the versatile Aurelien Rougerie.
Traille is neither an out-half (where he often plays for Biarritz) nor a full-back (where he often plays for France), but is at his most comfortable and effective in midfield.
France will be even better again when Lievremont eventually discovers that one of his replacements today -- the magnificent Yannick Jauzion -- can play a bit too.
The spin-off sees the brilliant, if unpredictable, Clement Poitrenaud recalled at full-back.
With the right tactics and right pressure, the Toulouse attacking flyer is vulnerable. But if allowed to do what he does best (counter from anywhere), he is possessed of that Blanco-esque ability to cut us to shreds.
We have in Luke Fitzgerald a player with the potential to hit the same off-the-cuff attacking heights.
Which one exerts the greater influence will reflect everything about the lie of the land further in.
It goes without saying that failure to front up will lead to defeat. Jamie Heaslip's return to action is of much more relevance to us than even the silky Poitrenaud is to France. Heaslip is our forward engine. He cranks it up in good times and bad. Both Sean O'Brien and David Wallace will be much better for his presence.
Despite last week's glitch, we are more formidable in the centre too. Rougerie (much like Tommy Bowe) is at his most effective wide on the right. Neither he nor Traille know what to expect of each other. As a pairing they are on a maiden journey into the unknown. The onus is on our experienced combination to capitalise on that before Jauzion makes his inevitable entry.
Against that, they now, at last, have what appears the real out-half deal in Francois Trinh-Duc -- a pivotal playmaker who exudes presence and variation in the still crucial game-running slot.
Forget this flexible 'first receiver' nonsense -- every team is at its best when its main man is in the primary position to launch an attack, particularly off the hoof. In Trinh-Duc, France have what appears the finished article.
From No 1 (Thomas Domingo) to No 8 (Imanol Harinordoquy) they are chiselled men. They can play ugly, but when the game opens up, they dance and skip over ground like prima ballerinas. It is an extraordinary mix, uniquely French.
So, what about Ireland? For starters, despite all the meticulous and scientific preparation associated with the modern-day professional game, being rank outsiders on home soil is a pretty good place to be.
This is, in so many ways, last week's pre-match psyche in reverse -- Ireland are where Italy were, France are where Ireland were.
The general feeling, based on most recent evidence, is that this match is Lievremont's to lose.
For Kidney, O'Driscoll, Paul O'Connell and the rest, it is about turning the clock back to times and methods past. It is about getting in French faces, under their skin, invading their territory and personal space, kicking with purpose, chasing with intent and generally making life hugely uncomfortable all round.
The new Lansdowne roar has still to be unveiled, but tomorrow is a chance for Ireland to get the crowd behind them and give them something to shout about.
In specific terms, we need a powerful tight-five performance. We need a varied and accurate line-out. We need Jonny Sexton asserting himself as we know he can. We need both centres back to their confident, problem-creating best. We need Fitzgerald cutting loose and making his favoured position definitively his for now.
But more than anything we need the fundamental accuracy that went AWOL in Rome. Passes must not alone stick, but must be presented for the receiver to run on to without checking stride.
Sympathy for the receiver is the essence of any smooth-running backline. Without it, all the skill, speed and experience in the world isn't worth a jot.
It is no secret that Joe Schmidt has gone back to these essentials at Leinster and we all know where that has led. Munster grit allied to Leinster panache is the unstated aim -- simple in theory, but at the highest level, extremely difficult to master.
Tomorrow, needs must. There is no alternative route to victory. As Willie Duggan used say in his inimitable way before big matches, "lads it's time to s**t or get off the pot." I doubt the current skipper could articulate it any better.
The force is with the visitors, but this smacks of one set to go to the wire.
Take Ireland to deliver, but France to edge it.