I was curious, after writing this, how accurate my take was, so I did a bit more reading on it. Short version, accurate overall, but the more detailed story is

I was curious, after writing this, how accurate my take was, so I did a bit more reading on it. Short version, accurate overall, but the more detailed story is much more interesting. First, in part, the intention of the Maginot line was to make the Germans go through Belgium. French planners assumed their German counterparts were smart enough not to attempt a direct assault on the line, and felt that a maneuver battle in Belgium was safe for them in terms of stopping the Germans there, after which they could settle into stable lines or possible attack through the Maginot Line. It wasn't literally a single road through the Ardennes, but the French did assume it was impassable and only weakly defended it; the Germans did gamble on attacking through the Ardennes and succeeded, flanking the French and British, forcing the evacuation at Dunkirk and permanently breaking the French lines. A few minor or weakly held forts in the Maginot Line were taken at the northern end, but none of the major forts were taken, the Italian invasion was stopped at the Line, and the Line was becoming the main point of resistance where French forces would hold out; German attacks against the main forts failed utterly. The defense of the Line was ended by the surrender of France.