Hitler had no idea the Soviets were so strong before invading

By the time Nazi Germany launched Operation Barbarossa, they were already at war with the British Empire, Yugoslavia, and Greece. Poland, France, and much of Western Europe had already fallen, but governments in exile joined the Allied effort against the Axis powers. So, the natural thing to do would be invade the world's largest country, right?

If you're Hitler, obviously, your answer is yes.

But Hitler just secured dominance of Continental Europe and was risking it by going up against a major world power with whom he had a treaty of nonaggression. Hitler's lebensraum theory aside, the reason he launched the 1941 attack on the Soviet Union is that he just didn't know how strong the Soviet Union actually was.

Intel and all that.

Yeah, no big deal.

There is only one audio recording of Adolph Hitler speaking in a conversational voice, as opposed to the multitude of films of the man making incendiary speeches at rallies and events. He is speaking with the Commander-In-Chief of Finnish Defense Forces Carl Gustaf Emil Mannerheim, who was engaged with the Third Reich in a war against the USSR.

"If someone had told me that a country could start with 35,000 tanks, then I'd have said, 'You are crazy!'," the German dictator told Mannerheim in the 1942 recording. "If one of my generals had stated that any nation had 35,000 tanks, I'd have said: 'You, my good sir, you see everything twice or ten times.You are crazy, you are seeing ghosts.'"

In the 11-minute audio clip obtained by the History Channel, Mannerheim and Hitler were recorded secretly by a Finnish engineer, since Hitler would never allow such recordings. The SS soon realized the dictator was being recorded and ordered the engineer to shut it off immediately. He was somehow allowed to keep it a secret — and he did, until 1957.

"It was unbelievable," he said of a factory in Donetsk that was able to produce some 3,000-6,000 tanks alone before the Nazis shut it down.

Unbelievable.

But Hitler goes on to say that even if he had known about the military and industrial capacity of the Soviet Union's massive centralized labor force and output potential, he would have invaded anyway. By the winter of 1939-1940, he says, it was clear there would be war between them. He just knew he couldn't fight the Soviets and the Western Allies in a two-front war — saying it would have broken Nazi Germany.

Well, he got that part right at least.

The Führer goes on to admit that the Germans were poorly prepared to fight a war in the extreme weather of the Eastern Front.

"Our whole armament, you know, is a pure good weather armament," He said. "It is very capable, very good, but is unfortunately just a good weather armament. Our weapons were naturally made for the West... and it was the opinion from the earliest of times: you cannot wage war in winter."

I'm pretty sure this depiction of Soviet General Winter is what inspired Metallica's "Enter Sandman."

Hitler goes on to talk smack about the "weakness of Italy," referring to Mussolini's failures in North Africa, Albania, and Greece, where German army and air assets were forced to divert from the buildup to invading the USSR to instead go rescue Italian troops being repulsed by the Greeks. Three entire divisions were sent to reinforce the Italians instead of invading Russia.

He believed the Soviets had their own designs on ruling all of Europe and that he had to launch when he did to keep them from capturing the oil fields in Romania, which Hitler believed would have been Nazi Germany's death blow — which wasn't entirely wrong.

That's why the U.S. Army Air Corps blew it up in 1943.

(U.S. Army)

Since the recording was cut off, no one really knows what else the two men talked about in their secret meeting that day, but it's believed that in that meeting, Mannerheim realized Hitler's position was weak and would no longer act subordinate to him for the duration of World War II.