Here follow 10 reasons why he lost the war.
10. His Allies in the Axis of Evil
Having no luck in enticing England to join in a fight against the USSR Hitler had to look for other, less powerful countries. Italy was the natural choice having an ideology similar to his but when WWII started their military equipment was already outdated. Other countries like Romania and Hungary were enticed in the Axis but neither could provide high-quality military assistance.
9 The Not One Step Back policyHitler saved the German army from catastrophic defeat in the winter of 1941 – 1942 when he ordered his troops to stand and fight the Russian counter attacks after the failed operation to capture Moscow. At that point, a decision to withdraw could well have caused a total collapse of the German front and early defeat in Russia.
After this, feeling vindicated, he took his policy too far and allowed not a single unit to withdraw, sometimes meddling down to regimental and even company level.
His decision to deny the German 6th Army at Stalingrad to withdraw caused it’s total defeat and in later battles or to deny withdrawing to more favorable terrain or to shorten the line caused the German Army countless casualties that it could ill afford.
8 The right technology used incorrectly
The Germans were well in advance of the Allies when it came to Military Technology. Vastly superior tanks and jet airplanes, mass produced and employed should have given the Germans an edge in any battle. However, the quest for ever heavier tanks instead of concentrating on mass production left the Germans with a wide array of tanks requiring different spares.
Also, the reliance on forced labor meant that quality control was a big issue, causing more frequent breakdowns which required more spares, etc.
7 Declaring War on the USA
On December 11, 1941, Germany declared war upon the United States, in response to what was claimed to be a series of provocations by the United States government when the US was formally neutral during World War II. This was 4 days after December 7, 1941 when the Empire of Japan launched an attack on Pearl Harbor.
According to the terms of the Anti-Comintern Pact, Germany was obliged to come to the aid of Japan if a third country attacked Japan, but not if Japan attacked a third country. Nevertheless, the German government chose to declare war on the United States.
This proved to be a godsend for both Churchill and Roosevelt who soon agreed on a Germany First strategy.
6. Hitler taking over as Commander-in-Chief
In December 1941 when the attack on Moscow stalled and the Soviets launched a massive counterattack which threatened to rout the Germans.
Hitler did not wish to accept this and he began removing officers from their command. Hitler clearly did not believe in giving back captured territory (see reason 9), so in the biggest shake-up of all, he declared himself commander in chief of the army. He would train it “in a National Socialist way”—that is, by personal fiat. He would compose the strategies and the officers would dance to his tune. (History.com)
5. Hitler did not listen to his GeneralsHaving won spectacular victories early in the war under his supervision Hitler considered himself a military genius. However, especially when the tides were turned in war, Hitler blamed his Generals for not carrying out his orders fueling further mistrust, in the end he only listened to himself (see reasons 9 and 6).
For instance, his plan to launch the Battle of the Bulge in December 1944, despite his Generals misgivings, caused Germany to lose valuable men and material making the job of the final defeat of Germany easier for the Allies.
4. The Russian Winter
Hitler was certain of a quick victory over the USSR, saying to his Generals “We have only to kick in the door and the whole rotten structure will come crashing down”, there was no need to prepare for the Russian winter as by then Russia would be defeated. However, being unable to capture Moscow and force a surrender meant his troops had to face the full onslaught of arctic cold in their summer uniforms.
3. The attack on Greece
Fully aware of the urgency to launch their assault on the USSR right after the thaw ended and Russian roads became passable again Germany ended up bailing out Italy (see reason 10) in their misadventure in Greece.
This military operation, even though Greece was taken quickly and thereby the Southern flank of the attack on Russian was now firmly secured, caused a 6 week delay of the attack on Russia. This delay meant that 6 autumn rains and then winter arrived before Operation Barbarossa was completed and the Russians destroyed.
2. Battle of Stalingrad
One of the costliest battles ever fought in war, the Battle of Stalingrad became a turning point for the second world war. Driving for the oil fields in the Caucasus the German 6th Army could have bypassed the or surround the city to take care of it later. However they went in full force, but being forced to fight for every city block, house and room causing massive casualties.
Then the Russians an offensive and surrounded Stalingrad and destroyed the 6th Army, which was not allowed to pull back (see reason 9).
1. A two front war
Hitlers prime target had always been Russia but to secure Germany’s western flank and avoid a war on two fronts Germany decided to attack France and Britain first. France was taken care off in a matter of weeks but having lost the Battle of Britain Hitler had only partially achieved securing his western flank. When he declared war on the USA (see reason 7) and had to fight Britain and the USA first in North Africa and then in Italy and later France Hitler was constantly dividing his forces.
Not being able to focus his full strength anywhere meant he could not force a decisive victory and ultimately invited defeat.