I'm not up on French history either, but I'd say it started about the time of our Revolution. Hundreds of thousands productive Europeans emigrated to the US, and it took us a little while to get our act together.
After the Brits wasted their men and capital in the US, they were too fatigued to harass the French, and complacency set in until WWI. For the next 80 years, the French grew used to the Brits and US saving their asses from the Germans and Russians.
That's where we're at today (at least IMHO).
But hey, like I said, I'm not up on French history.
So, kind of the frog in boiling water scenario...the decline was so slow, they have no idea they're in deep crap.
The question is, are they capable of realizing this means that there is no fence sitting in the war on terror. They can either break out their burkas and dust off their prayer mats or they can help us and Britain out.
I'm also sure they haven't figured out that if they think Christians are too strict and oppresive, they're in for a rude awakening when they get taken over by the Muslims...a VERY rude awakening...just ask the Afghani's.