“What exactly was AH thinking by declaring war on U.S.?”
1. He believed Japan to be much stronger than they actually were and the US would be tied up in the pacific.
2. He believed that it was only a matter of time before the US declared war on Germany since Germany was ‘allied’ with Japan.
IOW’s, he was doomed. He had no choice.
I still don’t get it. He didn’t need to declare war on U.S. just days after Pearl Harbor. He had his hands full in Russia in December 1941. Declaring war on the US should have been the last thing on his mind. His troops were dying of cold, starvation, and exhaustion on the Eastern Front by this time. Russian defenses were strengthening, a massive Russian counteroffensive was only weeks away. Of course AH couldn’t have known that on the day he declared war on the US. But there is no doubt that situation was turning against him as the brutal Russian winter was just arriving. Pure madness.