Comment: There's a common misconception about the famous Maginot Line, the massive series of fortifications built in the 1930s to defend France's eastern border from a German invasion.
That invasion came a few years later and ended with the country being occupied for the next four years, with ridicule aimed ever since at the Line not actually extending to the North Sea. The thing is, that was the whole point of it, to force their enemy to a favourable place where a decisive battle could be won.
Unfortunately, the Germans figured out another way in, but there can be a lesson learned from this history.
The All Blacks and Black Ferns are both battling France on Sunday morning and have been forced into positions that favour the home sides, with Ian Foster and Glenn Moore having to put out more reshuffled teams. Foster's hand has been forced, both through injury and the machinations of the way the tour has unfolded, with Aaron Smith set to make a return to the halfback spot to take on Antoine Dupont in what is being seen as a battle in itself of the world's best halfbacks.
In front of him will be Sam Cane, which again is another selection that probably wasn't in the original plans, but the need for leadership on the park after last weekend's meltdown in Dublin has seen Foster have to drop Dalton Papalii - arguably the form player of the whole tour. Papalii isn't the only one who can feel a bit miffed, while there is no doubting Smith's standing as one of the greatest All Blacks ever, it's not like there was anything wrong with the way Brad Weber has been playing this season.
Foster has rolled the dice and gone with Quinn Tupaea in the midfield, which makes this easily the biggest game of the 22-year-old's life. There's also going to be a lot of pressure on Akira Ioane and the bench.
While Samisoni Taukei'aho looks very much at home in test rugby, his set piece work will be a crucial factor if the game goes down to the wire. Meanwhile, Shannon Frizell and Damian McKenzie have hardly been setting the world on fire lately, but find themselves in line to close out a game that will go a long way to defining the All Black season.
There is one big factor in the All Blacks' favour, though. For all the talk about the unpredictability of France, a very tired narrative that really shows a lack of understanding of rugby in that part of the world, one thing you can reliably bet on is that they will lose to the All Blacks in Paris. The last French victory in the City of Lights came in 1973, a date significantly closer to the aforementioned Battle of France than today.
Down the road in Castres, Black Ferns coach Moore has again rung the changes as they try and salvage something out of what has now become an historically disastrous tour.
The words 'battle-hardened' and the Black Ferns' lack thereof have been a constant theme of the press conferences so far, but having been on the receiving end of three floggings in a row has meant that it rings a little hollow as they prepare to face a very impressive French side again. Those have been comprehensively lost battles, with the team showing few signs of actual improvement.
Last weekend's loss in Pau saw them barely able to get out of their own 22 and they conceded another truckload of penalties, which Moore lamented this week. In reality it could have been far worse, as the interpretation around contact to the head is an awful lot looser than in men's test rugby, and could have easily resulted in at least one red card.
Veterans Kelly Brazier, Kendra Cocksedge and skipper Les Elder have an awful lot of pressure to perform after some very questionable tactical decisions in the first three tests, with simply too much valuable possession booted away to opposition eager to just run it straight back at them and score.
Make no mistake, these are two big battles in France this weekend. The All Blacks and Black Ferns are right where the French men and women want them, banged up and at the end of long tours. They need to find a way in, to take on the French on their terms instead.