[removed]

The military leaders in charge during the most successful stages of the war were replaced by those closer aligned with Hitler politically. They were not good enough to repeat the successes of their predecessors. Hitler also made a huge mistake of opening hostility upon Russia. The new front divided the countries resources, and Germany couldn't fully utilize the armies, and armaments of the countries they occupied as they moved east. They just couldn't move fast enough.

Nazi Germany tried to attack the three largest empires in existence at the same time, with the assistance of two other middling powers. They were dwarfed in population, dwarfed in available resources, and dwarfed in industrial capacity. Their only hope was that the populations of those empires would be unwilling to actually fight and would surrender/negotiate for peace after a few defeats.

Mostly a numbers game but some pretty bad decisions were also made especially later in the war. The US was the largest industrial power by a wide margin and practically immune to attack on the mainland. Germany could never match the sheer output and in a total war the larger economy is going to win eventually.

The biggest strategic mistakes were going to war with the US when they didn't necessarily have to, choosing to fight a 2 front war and continuing to fight Britian when they had no real chance of winning quickly. Really you would need to change all 3 of these for Germany to have any real chance of winning.

Without wanting to get too far into a massive subject: it's important to keep in mind that invading the Soviet Union was a key Nazi goal. In their minds, the land and resources were needed to make Germany strong enough to stand against the British Empire and the United States. So what looks like a strategic mistake was really a key goal of the war for Nazi Germany.

Those military planners were probably right that they wouldn't get a better chance later... Which just goes to show how far their goals were from their ability to reach them. (A mistake not entirely unrelated to the whole "slavs are subhuman, Germans are superior" thing...)

Please read this entire message

Your submission has been removed for the following reason(s):

Whole topic overviews are not allowed on ELI5. This subreddit is meant for explanations of specific concepts, not general introductions to broad topics.

If you would like this removal reviewed, please read the detailed rules first. If you believe this submission was removed erroneously, please use this form and we will review your submission.

[deleted]

There is no ELI5 answer to a question of this complexity. Seriously it happened 80 years ago and it is still an active topic for serious inquiry.

My top most opinion is Germany underestimated the Soviet union's ability and commitment to fighting.

Germany and The Soviet Union had a non-aggression treaty to divide Poland. If the Germans had abided by the agreement they would not have expended so much of their resources in the Eastern front and might have successfully controlled Western Europe.

https://www.britannica.com/event/German-Soviet-Nonaggression-Pact

TLDR: They stretched themselves out too far, too fast, and fought too many enemies at the same time. They ran out of raw materials, and lost all of their best leaders.

The Nazi's needed to maintain a technological superiority to overcome their lack of natural resources. By the end of the war the allies had mostly caught up and had the industrial might of the USA backing them up and supplying them.

After some early successes in Europe they became over confident and began attacking on too many fronts at once.

Once the Soviet Union got involved the Nazi's couldn't compete with the massive weight of bodies and industry the Soviets could throw at them. While the quality of the Soviet Unions troops and equipment was very poor their sheer numbers overcame their disadvantages. The Nazi's highly trained personnel couldn't be replaced quickly enough and their advanced weapons could no longer be made in adequate quantities.

The Nazi's were also running out of key raw materials like metal and Oil. So even if they had the planes and tanks, they couldn't fuel them.

By the end of War Hitler had replaced all his competent generals with people loyal to him (yes men) and he had taken personal control over many military decisions. Hitler became deluded and was being affected by his addiction to various medications. He made bad decision after bad decision, and several failed attempts to kill him arguably made the Allies job easier.

The loss of the Battle of Britain is cited as the beginning of the end. If Britain had been captured, or invaded it's far less likely that the US would have stepped in to help them directly and instead would have focused 100% on the Far East.

That and the Italians were idiots. Some historians argue that the Italian military was so inept that they consider them to have been on the side of the allies.

Hitler took direct control of Russia offensive overruling the operational generals (whose superiors feared Hitler and were making mistakes in their craven support of him). Long supply lines, the brutal winter :- both were impediments … ; the unnecessary declaration of war on US: perhaps tactical focus on Moscow alone rather than pushing also elsewhere at same time could’ve pushed them to win Moscow; and no declaration on US would’ve helped … but in the end these are exactly tactical arguments. As is Eloquently stated above: strategically they could not win: was it inevitable? By lack of resources yes, but the ruthless soviet commitment (and bravery) was stalling the German army effectiveness by a sheer numbers game (a sobering lesson to recall) … : In the end economic might and a war on 2 fronts … Germany were declining and the end game was set in 1941; and leadership was crucial: Churchill / Roosevelt turned US opinion…to support brutal Stalin: all whilst the increasingly isolated Hitler depended on personal control : his erratic decisions were both the cause of the war and the reason Germany lost. If his ambitions were less he could have held more for longer … but that simply wasn’t an option for him/his ideology.