Fall of the Low Countries and France
In October 1939, accepting the fact that the conquest of Poland, however impressive, would not prompt Great Britain and France to withdraw from the war, Adolf Hitler directed the High Command of the Armed Forces (Oberkommando der Wehrmacht or OKW) to prepare for an offensive in the west. Although the leading German commanders believed the better course to be to await an Allied offensive, he insisted on striking within six weeks in order to forestall further Allied preparations. The first version of the plan for the attack, called Fall Gelb (Plan Yellow), was modeled on the old Schlieffen Plan, which had received a modified test in 1914. It was based on a main effort through Belgium north of Liege. A total of 37 divisions was to make this effort, while a subsidiary force of 27 divisions moved through the Ardennes region of Belgium and Luxembourg.
This was exactly what the Allied commanders expected. An attack against northeastern France was improbable because of the existence of the Maginot Line, the formidable belt of fortifications built in the 1930’s from Switzerland to Longuyon, near the junction of the borders of Belgium, Luxembourg, and France. Because of the barrier of the hilly, forested Ardennes, Allied commanders considered a major attack there also improbable. Thus only the Liege area, leading to the flatlands of Flanders and thence to France’s northern frontier, was supposedly open to the Germans.
Though built originally merely to protect Alsace and Lorraine until France could mobilize against a surprise attack, the Maginot Line had engendered a false sense of security in the warweary country. French commanders were nevertheless conscious of the great gap reaching from the end of the line to the English Channel. They accepted the fact of the gap on the theory that France could not afford to fight along this line. In the first place, battle in the industrial LilleCambrai region would destroy or deny two thirds of the nation’s coal resources. Secondly, accepting battle there would mean acquiesence in the surrender of Belgium. This France, victor over Germany in World War I and still a major power with reputedly the world’s strongest army, could not accept.
It was apparent to French and British leaders that once the Germans attacked, the Allies had to move into Belgium. To provide time for this movement the Allied leaders depended on a delaying action by the Belgian Army, reinforced by the barrier of the Ardennes and the Meuse River, the large forts at Liege, the deep cut of the Albert Canal north of that city, and Fort EbenEmael near the Dutch-Belgian border. ( This fort was said to be the strongest single fortress in the world.) The major problem was the lack of consultation and coordination with the Belgians and the Dutch. Although the Low Countries realized that Nazi Germany would include them in any pattern of conquest against the West, they continued to hope that a policy of abject neutrality would forestall the inevitable.
The Allies planned nevertheless to advance into Belgium to the line of the Scheldt (Escaut, Schelde) River (Plan E). As the months passed without a German attack and the British Expeditionary Force (BEF) was increased to 10 divisions, this plan was replaced by a more ambitious decision to move to the Dyle River, a few miles east of Brussels (Bruxelles). Under Plan D, as the new concept was called, the Belgian Army was to fall back on the Dyle and the lower reaches of the Albert Canal to protect Antwerp (Antwerpen), the British were to defend the upper Dyle, and the French were to hold the Gembloux gap between the Dyle and the Meuse at Namur (Namen) and the Meuse itself where the river crosses the Ardennes. In the continued belief that the main German effort would be made in the Liege area, the supreme French commander, Gen. Maurice Gustave Gamelin, assigned to the Gembloux gap his strongest force, the mechanized First Army under Gen. Georges M. J. Blanchard. The second strongest force, the Seventh Army under Gen. Henri Giraud, ostensibly a reserve, was to move swiftly into the southern Netherlands to assist the Dutch. In keeping with the theory that the Ardennes itself was a considerable barrier, a weaker force, the Ninth Army under Gen. Andre Georges Corap, was to defend the Meuse from Namur to Sedan; and another weak force, the Second Army under Gen. Charles Huntziger, was to serve both as a bridge between Sedan and the garrison of the Maginot Line and as a hinge for the wide-swinging movement of the Allied armies into Belgium.
As the Germans prepared for attack in November 1939, an invasion scare gripped the Allies, but bad weather forced postponement of the attack. After repeated postponements because of weather conditions, the attack was firmly scheduled for Jan. 17, 1940. A week before the target date, however, a German plane strayed off its course and was forced down in Belgium. On the two officers aboard the Belgians found orders for the air phase of the invasion. This prompted an alarm of even greater proportions than before, and some French forces began moving toward their assigned sectors along the Belgian border. German observers could not help but note the nature of the French deployment, particularly the weakness of the armies at the hinge near Sedan. Of even greater consequence was the fact that the information gained from the fliers confirmed General Gamelin’s view that the invasion was to come through the Liege area and not through the Ardennes.
In the meantime, Hitler and several of his subordinates had begun to question the basic concept of Plan Yellow. Indeed, even before the November target date, Hitler himself had forced a change in plan that shifted the main effort from north of Liege to both sides of the city. Col. Gen. (later Field Marshal) Gerd von Rundstedt, commander of Army Group A, which was to drive through the Ardennes, insisted that the main effort be made through that sector with armored divisions to the fore. In an audience with the German leader, Rundstedt’s chief of staff, Lt. Gen. (later Field Marshal) Erich von Manstein, apparently provided the final arguments needed to change Hitler’s mind. After weather again forced the cancellation of the target date, Hitler postponed the offensive until spring and ordered a basic alteration in the plan. Army Group B in the north, commanded by Col. Gen. Fedor von Bock, was reduced to 28 divisions, only 3 of which were armored. Rundstedt and Army Group A in the Ardennes had 44, including 7 armored divisions. With the main thrust moving via Sedan, Rundstedt was to drive to the channel, trapping French, British, and Belgian armies in Belgium.
Meanwhile, the Allies failed to profit materially from the eight months’ respite that they had gained between the declaration of war and the onset of major hostilities in the west. They still felt no real sense of crisis, for they continued to consider the speed of the Polish campaign attributable less to German strength and to a new mode of warfare than to Polish weakness. Although some effort was made to extend the Maginot Line fortifications to the coast, it produced little more than a shallow antitank ditch and a few widely spaced blockhouses. Modern equipment for the French armies and the BEF remained a promise rather than a reality. Allied timetables for troop movements still resembled those of World War I. Corap’s Ninth Army, for example, planned on five days for the move to the Meuse covering the Ardennes while only cavalry units sought to delay the Germans east of the river. The Allies, and particularly the French, still looked on tanks as servants of the infantry, parceling them out to infantry divisions rather than massing them in hard-hitting armored formations in close liaison with tactical aircraft.
The Allies actually were superior numerically to the Germans. The French, Dutch, Belgians, and British together had approximately 4,000,000 men available, in contrast to about 2,000,000 Germans who might be used against them. As of May 1940, 136 German divisions were in the west, as opposed to 94 French divisions in northeastern and northern France, plus 10 British, 22 Belgian, and 9 Dutch divisions. In tanks, too, the opposing forces were relatively equal. The Germans had 2,439 tanks in the west; the Allies, 2,689. Nor were German tanks vastly superior except in speed. Created as infantry support weapons, French tanks were heavily armed and armored but lacked appreciable speed and cruising range. In aircraft the Germans enjoyed some advantage in over-all numbers, with about 3,200 planes to 1,200 French and 600 British planes, but in fighter aircraft alone the two forces were approximately equal. Only in antiaircraft and antitank weapons were the French markedly inferior. The difference in opposing forces thus was less a question of numbers and quality than of a variance in approach to modern warfare. The Germans had developed new methods based on quick breakthroughs by armor supported by mobile artillery and aircraft, followed by rapid exploitation of the resulting gaps. In addition, a kind of war-weary lethargy still gripped both France and Britain, as is evidenced by their relatively slow industrial mobilization. Not until Hitler invaded Denmark and Norway in April 1940 was the full portent of the Nazi threat accepted in the two nations. By that time it was too late.