When the German armies began to retreat, Hitler dismissed Brauchitsch and personally took command. He always maintained thereafter that he personally… - Adolf Heusinger

In 1939 Hitler assured Brauchitsch that England and France would not declare war when Germany moved against Poland. The general staff expected a war of two or three months’ duration. After France and England declared war, the opinion was that it would last a long time, but no definite time was predicted. Both Brauchitsch and the chief of the general staff had grave doubts as to Germany’s ability to conduct a prolonged struggle. In the general planning it was estimated that we would require a four months’ reserve of armaments and munitions to carry through the period of conversion to war production. At the outbreak of the war, however, we had only a two months’ reserve. This gap was bridged during the inactive period of the war between the Polish and western campaigns.

The general staff was of the opinion that a French attack in the west would have broken through, as our fortifications were not complete, nor were they in 1939, when the French could have broken through, although at heavier cost. The West Wall was completed only from Trier south to the Rhine in 1939. Northward it was incomplete and without any depth. After 1940 construction ceased. To a certain extent the West Wall was a bluff, like the Atlantic Wall. With regard to the latter it was impossible to fortify the entire coast and every military man must have concluded that a landing and a penetration of five kilometers would end all difficulties as far as fortifications were concerned.

The first plan for an offensive campaign [in the West] was formulated in November 1939. In substance it was a repetition of the 1914 Schlieffen plan. As the start of the campaign was delayed, doubts arose as to the achievement of any surprise with this plan. The basic idea of the new plan—the breakthrough in the Ardennes, crossing of the Meuse, and the trapping of British, French and Belgian forces in the north by pushing the tank forces through to the Channel—came to several minds at once. And in justice it should be said that one of these was Hitler’s. However, General Manstein, then chief of staff to Marshal Rundstedt, deserves the greater credit. He worked out the plan and proposed its adoption. The order was given to the Operations Division in February 1940 to replan the campaign along the proposed lines. From February 1940 to May 1940 the plan was subject to the sharpest criticism. Among the critics was General Guderian, who described the plan as a ‘crime against Panzers’. General Halder deserves the credit for defending the plan against all critics and insisting upon its execution. General Bock was also opposed to it and appealed to the chief of the general staff. Halder said once that he would stick to the plan if the chances of succeeding were only ten percent.