History doesn't happen in a vacuum.
My children learned early on that asking me a simple question of a historical or political nature would most often not elicit a short, simple answer. History is not, as our failing educational system portrays, simply a chronological countdown of names, dates, places, and events. Human history is a complex tapestry of interconnected threads; the unraveling of any one such thread will lead you on a dizzying ride through man's experience on this big blue marble. Often a thread placed in the weave at one part of the cloth will not join a cohesive pattern until it has wound its way to another part. Today's history lesson is case in point.
Ninety-one years ago, the European antagonists in the first great war of the 20th Century were deadlocked in a war of immobile attrition along a line of trenchworks stretching from the Baltic to the Alps. The machine gun, barbed wire, massed artillery, and observation by aircraft had rendered infantry and horse cavalry formations incapable of the successful offensive action required for victory in war (no war has ever been won on the defense). On the 20th 0f November, 1917, A British offensive employing 450 armored and armed tractors (tanks) surprised and overwhelmed the German defenses near Cambrai. The shortsighted operational and strategic planning typical of the Anglo/Franco Alliance in this war prevented exploitation of the breach in the enemy's static defensive lines and the Germans quickly restored stalemated positions.
There were huge lessons to be learned from this event that would be studied and implemented to stunning operational success nearly 23 years later. In 1940, the French tank was actually a better armored vehicle than the one employed by the German army. French reliance on static defenses at the Maginot line, with tanks spread our in infantry supporting roles, demonstrated failure to learn the lesson of Cambrai. The Germans, having suffered defeat at the hands of mobile armored formations at Cambrai, incorporated the tactic in their mobile, high tempo Blitzkrieg and overran the French and English forces in France and the Low Countries in June of 1940.
The German success is nearly universally credited to their military genius. No genius--just good appreciation of history.