Quote Originally Posted by Evil_Maniac From Mars
What difficulty/agressiveness level are you playing? The AI never leaves the Maginot unguarded in my campaigns, even using your tactics. I'm always forced to go through Belgium or a country that's allied to me, such as Italy.
You can always go around and disembark in Normandy. Sometimes you just get lucky with the British navy thing. Though with proper preparations the Kriegsmarine can easily be brought up to standard to blow the Brits out of the water. Either way, if you want to win in the West, a Navy is necessary, since taking the British isles is a bit of a problem, due to the rather random nature of encounters on the sea.

However, the important thing to remember, the Netherlands will join the allies the moment the Japanese declare war on them, those islands in the Pacific are mighty attractive (especially with the oil). Belgium, not so much, but the Netherlands will join the allies, unless you bring them into another alliance.

As to overwhelming the Maginot line ... well, with enough airpower, that can be done. Tac bombers set on Interdict, given enough numbers, time and fighter support can weaken the French enough to take the territory with support from paras and armour, but that is far too expensive so early in the war, and, unless you opt for peace in Danzig or War, it's unlikely that Germany has enough resources for such a conflict.