The original German plan of attack in the West had been drastically changed since it fell into the hands of the Belgians and, as the Germans suspected, of the French and British, in January. Fall Gelb (Case Yellow), as the operation was called, had been hastily concocted in the fall of 1939 by the Army High Command under the pressure of Hitler’s order to launch the offensive in the West by mid-November. There is much dispute among military historians and indeed among the German generals themselves whether this first plan was a modified version of the old Schlieffen plan or not; Halder and Guderian have maintained that it was. It called for the main German drive on the right flank through Belgium and northern France, with the object of occupying the Channel ports. It fell short of the famous Schlieffen plan, which had failed by an ace of success in 1914 and which provided not only for the capture of the Channel ports but for a continuation of a great wheeling movement which would bring the German right-wing armies through Belgium and northern France and across the Seine, after which they would turn east below Paris and encircle and destroy the remaining French forces. Its purpose had been to quickly put an end to armed French resistance so that Germany, in 1914. could then turn on Russia with the great bulk of its military might.
But in 1939–40 Hitler did not have to worry about a Russian front. Nevertheless his objective was more limited. In the first phase of the campaign, at any rate, he planned not to knock out the French Army but to roll it back and occupy the Channel coast, thus cutting off Britain from its ally and at the same time securing air and naval bases from which he could harass and blockade the British Isles. It is obvious from his various harangues to the generals at this time that he thought that after such a defeat Britain and France would be inclined to make peace and leave him free to turn his attention once more to the East.
Even before the original plan for Fall Gelb had fallen into the hands of the enemy it was anticipated by the Allied Supreme Command. On November 17 the Allied Supreme War Council, meeting in Paris, had adopted “Plan D,” which, in the event of a German attack through Belgium, called for the French First and Ninth armies and the British Expeditionary Force to dash forward to the principal Belgian defense line on the Dyle and Meuse rivers from Antwerp through Louvain, Namur and Givet to Mézières. A few days before, the French and British general staffs, in a series of secret meetings with the Belgian High Command, had received the latter’s assurance that it would strengthen the defenses on that line and make its main stand there. But the Belgians, still clinging to the illusions of neutrality which fortified their hope that they yet might be spared involvement in war, would not go further. The British chiefs of staff argued that there would not be time to deploy the Allied forces so far forward once the Germans had a tacked, but they went along with Plan D at the urging of General Gamelin.
At the end of November the Allies added a scheme to rush General Henri Giraud’s Seventh Army up the Channel coast to help the Dutch north of Antwerp in case the Netherlands was also attacked. Thus a German attempt to sweep through Belgium—and perhaps Holland—to flank theMaginot Line would be met very early in the game by the entire B.E.F., the bulk of the French Army, the twenty-two divisions of the Belgians and the ten divisions of the Dutch—a force numerically equal, as it turned out, to that of the Germans.
It was to avoid such a head-on clash and at the same time to trap the British and French armies that would speed forward so far that General Erich von Manstein (born Lewinski), chief of staff of Rundstedt’s Army Group A on the Western front, proposed a radical change in Fall Gelb. Manstein was a gifted and imaginative staff officer of relatively junior rank, but during the winter he succeeded in getting his bold idea put before Hitler over the initial opposition of Brauchitsch, Halder and a number of other generals. Manstein’s proposal was that the main German assault should be launched in the center through the Ardennes with a massive armored force which would then cross the Meuse just north of Sedan and break out into the open country and race to the Channel at Abbeville.
Hitler, always attracted by daring and even reckless solutions, was interested. Rundstedt pushed the idea relentlessly not only because he believed in it but because it would give his Army Group A the decisive role in the offensive. Although Halder’s personal dislike of Manstein and certain professional jealousies among some of the generals who outranked him led to Manstein’s transfer from his staff post to the command of an infantry corps at the end of January, he had an opportunity to expound his unorthodox views to Hitler personally at a dinner given for a number of new corps commanders in Berlin on February 17. He argued that an armored strike through the Ardennes would hit the Allies where they least expected it, since their generals probably, like most of the Germans, considered this hilly, wooded country unsuitable for tanks. A feint by the right wing of the German forces would bring the British and French armies rushing pell-mell into Belgium. Then by cracking through the French at Sedan and heading west along the north bank of the Somme for the Channel, the Germans would entrap the major Anglo–French forces as well as theBelgian Army.
It was a daring plan, not without its risks, as several generals, including Jodl, emphasized. But by now Hitler, who considered himself a military genius, practically believed that it was his own idea and his enthusiasm for it mounted. Halder, who had at first dismissed it as a crackpot idea, also began to embrace it and indeed, with the help of his General Staff officers, considerably improved it. On February 24, 1940, it was formally adopted in a new OKW directive and the generals were told to redeploy their troops by March 7. Somewhere along the line, incidentally, the plan for the conquest of the Netherlands, which had been dropped from Fall Gelb in a revision on October 29, 1939, was reinstated on November 14 at the urging of the Luftwaffe, which wanted the Dutch airfields for use against Britain and which offered to supply a large batch of airborne troops for this minor but somewhat complicated operation. On such considerations are the fates of little nations sometimes decided.5
And so as the campaign in Norway approached its victorious conclusion and the first warm days of the beginning of May arrived, the Germans, with the most powerful army the world had ever seen up to that moment, stood poised to strike in the West. In mere numbers the two sides were evenly matched—136 German divisions against 135 divisions of the French, British, Belgian and Dutch. The defenders had the advantage of vast defensive fortifications: the impenetrable Maginot Line in the south, the extensive line of Belgian forts in the middle and fortified water lines in Holland in the north. Even in the number of tanks, the Allies matched the Germans. But they had not concentrated them as had the latter. And because of the aberration of the Dutch and Belgians for neutrality there had been no staff consultations by which the defenders could pool their plans and resources to the best advantage. The Germans had a unified command, the initiative of the attacker, no moral scruples against aggression, a contagious confidence in themselves and a daring plan. They had had experience in battle in Poland. There they had tested their new tactics and their new weapons in combat. They knew the value of the dive bomber and the mass use of tanks. And they knew, as Hitler had never ceased to point out, that the French, though they would be defending their own soil, had no heart in what lay ahead.
Notwithstanding their confidence and determination, the German High Command, as the secret records make clear, suffered some moments of panic as the zero hour drew near—or at least Hitler, the Supreme Commander, did. General Jodl jotted them down in his diary. Hitler ordered several last-minute postponements of the jump-off, which on May 1 he had set for May 5. On May 3 he put it off until May 6 on account of the weather but perhaps also in part because the Foreign Office didn’t think his proposed justification for violating the neutrality of Belgium and Holland was good enough. The next day he set May 7 as X Day and on the following day postponed it again until Wednesday, May 8. “Fuehrer has finished justification for Case Yellow,” Jodl noted. Belgium and the Netherlands were to be accused of having acted most unneutrally.
May 7. Fuehrer railroad train was scheduled to leave Finkenkrug at 16:38 hours [Jodl’s diary continued]. But weather remains uncertain and therefore the order [for the attack] is rescinded … Fuehrer greatly agitated about new postponement as there is danger of treachery. Talk of the Belgian Envoy to the Vatican with Brussels permits the deduction that treason has been committed by a German personality who left Berlin for Rome on April 29 …
May 8. Alarming news from Holland. Canceling of furloughs, evacuations, roadblocks, other mobilization methods … Fuehrer does not want to wait any longer. Goering wants postponement until the 10th, at least … Fuehrer is very agitated; then he consents to postponement until May 10, which he says is against his intuition. But not one day longer …
May 9. Fuehrer decides on attack for May 10 for sure. Departure with Fuehrer train at 17:00 hours from Finkenkrug. After report that weather situation will be favorable on the 10th, the code word “Danzig” is given at 21:00 hours.
Hitler, accompanied by Keitel, Jodl and others of the OKW staff, arrived at headquarters, which he had named Felsennest (Eyrie), near Muenstereifel just as dawn was breaking on May 10. Twenty-five miles to the west German forces were hurtling over the Belgian frontier. Along a front of 175 miles, from the North Sea to the Maginot Line, Nazi troops broke across the borders of three small neutral states, Holland, Belgium and Luxembourg, in brutal violation of the German word, solemnly and repeatedly given.