What were two major mistakes of the Axis Powers in World War 2?

Answer 1

I will name a mistake the Japanese and the Germans did.

First, I'll start with Nazi Germany. The Germans made their mistake way before the Second World War was started; They elected Hitler as the leader of Germany, their Fuehrer. Hitler was, no doubt, a madman, and that alone was what led Germany to defeat. If they had a different leader, perhaps they could have won WWII. See, Hitler believed that Germany was the greatest nation in the world, and in his unbelievable amount of "patriotism", he overthought his nation's military strength, and this is one of the mortal flaws in the Art of War.

Second, I will name the Japanese: They could very well have taken over Asia and named themselves the Japanese Empire in today's politics. They could have done this very easily, and they technically made themselves lose. Their mistake was attacking Pearl Harbor. They overestimated American will and, in trying to gain control over Asia, they attacked Pearl Harbor, thinking that this would make the US not get involved of the takeover of Asia. However, they were miserably wrong and the US, completely what Japanese military commanders had not expected, stood to their feet and was able to win the key to to the door that led to today's history's house, and this golden key was named Midway Atoll. It is ironic that the Japanese, having the biggest battleship in the world (the Yamato) and some of the greatest military tacticians (namely Yamamoto), who had the capability to grab the key that would lead to the guest of the Japanese Empire in the house of our history, had lost on account of underestimation.

So, you see, the Axis made two very, very clear mistakes during the Second World War. My sources is the books I have read. I am no liar.
1.[Germany] Operation Barbarossa - The pressure put on Germany because of the operation, by forcing them to fight a two front war, caused Germany's downfall. If Germany focused on capturing the British Isles first, they could then carry out Operation Barbarossa, and capture the western Soviet Union.

2.[Japan] Attack on Pearl Harbor and other American territories - Although it is possible FDR would have considered war, it's likely that if Japan invaded all southeast Asian territories except American ones. Even if the United States declared war, the largely isolationist population would get angry over the fact that there was no real casus belli, and there would likely be very little support for the war, and Japan would either win a war of attrition if the US declared war, or be able to build a large enough fleet to go to war with the US, or completely avoid the US.