Its hard to grasp the sheer magnitude of Operation Barbarossa and subsequent operations on the Eastern Front in World War II. We’ve seen nothing like it since. Other fronts, like the Pacific, North African, and the Italian and French theaters were but side shows to this main event. The only exception which comes close was the Japanese invasion of China, starting in 1937.

This was a war of annihilation.

4.5 million Soviet troops lay dead by the end of 1941, according to historian David Glantz.

The Germans suffered 750,000 casualties.

You’d think that the Wehrmacht should have, in the end, won. But Hitler and his high command had underestimated the number of divisions Soviets could raise. You can read about this in detail in Glantz’s The Colossus Reborn.

Another reason the Germans failed to achieve there objectives was, in part, because they were often ill-equipped. The vast majority of the Wehrmacht entered Russia on foot, using horses and wagons. The image of an unstoppable German blitzkrieg filled with tanks and bombers is largely a myth, probably fueled by German propaganda and Western allies trying to explain how Nazi Germany conquered so much of Russia.

Furthermore, the strength of forces that appeared paper at times didn’t reflect the reality in the field. The 1st SS Panzer Division Leibstandart SS Adolf Hitler (pictured above) started World War II as a regiment, became upgraded to a reinforced brigade (just over 6,500 troops), but it wasn’t a full division (12,000 troops) for Operation Barbarossa.

The blitzkrieg worked well in smaller countries, for the most part, not so much in Russia. An armored pushed can only be sustained for only about 250 miles, assuming a constant forward advance without any major troubles. Then the tanks and other vehicles must stop, refuel, and wait for the infantry to catch up to defend against any possible counterattack or to move forward again.

Nazi Germany also had one more factor which hindered its progress and ability to re-equip and re-supply its troops in the field: its economy. The Third Reich didn’t order full time war production until September of 1944.

Hitler and his high command had expected Russia to collapse by the end of Summer 1941, or Christmas at the latest. Why would there be a need for Germany to convert its economy for total war?