Answer:
The Allies saw the German military strength as powerful, but not innovative, thinking they would mirror the war of 1914.
Explanation:
During the first phase of the war, the French High Command pivoted the war strategy, but they were hindered in their fear of repeating the trench war of 1914. Thus their strategy was entirely defensive, hoping that the German military (no matter its power) would crash against the Allied superior numbers and its defenses (in short the Maginot Line).
They were sure that technology was not adavanced enough to overcome certain natural spaces, and though short of the German innovativenes, that was the cause of the attack through the Ardennes, and then the pincer movement that would lead to Dunkirk and the French defeat and surrender in 1940.
