How come Germany in WW2 was so sure they could defeat Russia whilst already at war with everyone else?
How does one calculate profits and loss when it comes to going at war with another country?
A part of it is the technological advantage but how do you calculate odds for sheer manpower? Do add up your soldiers, tanks and ships and then say let's do this?
I am sure that there is no textbook formula and a lot comes down to wishful thinking. But if I'm the guy who has to look at the numbers - free from emotion / ideology - how do I draw conclusions to advise those in charge?
But if I'm the guy who has to look at the numbers - free from emotion / ideology - how do I draw conclusions to advise those in charge?
Sometimes the people making the recommendations flat-out get it wrong, despite their best intentions and lack of emotion. For instance, during the entirety of the Battle of Britain the British overestimated German fighter strength (both in terms of pilot and planes). So, throughout the battle the British were convinced that they were just barely hanging on to their survival. At the same time, the Germans consistently underestimated British fighter strength (again, both in terms of pilots and planes). So, throughout the battle the Germans were sure they were very close to victory. The reality was that the British were winning the war of attrition from the very beginning (an earlier thread on the topic for reference) and the Germans were hemorrhaging pilots and planes at an unsustainable rate for results that weren't enough to knock the RAF out of the fight.
Why?
Neither side had an accurate understanding of their enemy. It wasn't emotion and it wasn't really ideology, both sides just got the numbers wrong. People did their best and still got it wrong. That happens quite often. So how do you calculate your chances during a war? Sometimes you do it poorly.
The problem is you are looking at the situation with hindsight. At the time, there is no such determinism. In your example, Hitler had just beaten France, Britain was badly damaged (more so every night with the air raids), and the United States was not yet in the war. He likely felt unstoppable (most of the world thought he was in 1940), and his confidence in a Russian campaign was beyond high. Sure, you could say "Napoleon fell victim to the same hubris", but at the time, Hitler could have shrugged off the Napoleonic example by citing the Luftwaffe's technological superiority (something Napoleon never had), or how the issues of Spanish subversion and domestic disorder in 1812 hindered the Moscow campaign. If you were looking at the situation from the point of view of the average person in 1941, you would probably guess that Hitler had a better than even chance of conquering the Soviet Union.