So the above image captures a general perception held by many, how could France, a modern military power in 1940, rely upon a forest to stop the largest armored assault in history – in many sources the French defense in 1940 is treated as a textbook example of a nation failing to properly understand the potential of German tanks and in the common teaching of the war the above joke is treated as a serious point of military history. The conventional wisdom is “France was expected a retread of the attack through Belgium and Germany totally got the drop on them by punching through the forest which France stupidly relied on as am impenetrable barrier against tanks.” The first thing to explain is that France, and Great Britain’s expectation of a retread of the German World War I invasion plan through Belgium was actually pretty reasonable, it was the plan the Germans were working with up until late February 1940 and the plan favored by most of the German military leadership. (For perspective the invasion of France, Belgium, and Holland started on 10 May 1940 so a two month major change of plans was uncommon for a major military offensive.) The original German plan was basically the World War I invasion plan beefed up with tanks and aircraft, however the problem was that the German high command, in anticipating the French and British response, expected high German causalities and the offensive winding down with the German army holding about half of Belgium. Enter the German general Eric von Manstein with his crazy “up the center” plan to invade France.
Manstein (pictured above) suggested the famous thrust through the Ardennes forest as the major offensive effort, breaking through the French army at that location, and then pouring troops through into the open territory behind French lines and trapping the Franco-British combined armies that had moved into Belgium behind a fast moving German military movement. The reason the rest of the German military leadership disliked this plan was it was incredibly risky, had the French facing the German military breakthrough mustered any of the following three things: massed tank formations to crush the German armored columns, massed successful air offensive against the German leading tank formations, or French infantry with sufficient anti-tank artillery to contain the breakthrough. Now Manstein could feel confident the first two would not happen, for reasons outlined below, but the last item was the one that was uncertain, bluntly put it would not take much French infantry with proper anti-tank weapons to delay the German breakthrough for long enough for the French and British to realize “Oh crap, attack up the center, shift reserves there” and then the brilliant lightening stroke would have turned into a nasty mess with Germany’s fine military suddenly caught in a trap of its own making.
Furthermore the French military command actually did see the offensive potential of a German breakthrough in the Ardennes forest, battles had been fought there in World War I and as early as 1938 the French high command understood the Ardennes was not sufficiently strong as a barrier to prevent German tank offensives without “special preparations in advance.” The military commander of the French forces in World War II, Marshall Maurice Gamelin (pictured above) argued prior to the war that not only was the point that Germany later smashed through defensively weak but pushed to have it re-enforced in defense. Specifically the town of Sedan, considered a linchpin defensive point, was found by multiple French military leaders to be insufficient to prevent a serious attack. The problem was an easy solution was not present – building heavy fortifications would be expensive and arguing that the Ardennes was sufficient as a defensive point also helped deter French politicians from requiring the massive Maginot line be extended into the region, which would have siphoned off French economic resources for other military improvements that the French military leadership thought more critical – such as more advanced aircraft and more armor.
So what happened when Germany invaded and why, even knowing the danger in advance, did France fail to properly stem the German attack through the Ardennes forest? That’s a story for a second installment next week…