The French and the Brits were going to WWI without the US it just may have taken longer which would have hardly mass things better. British tanks did more to break the stalemate than th US did. You sound like hair pulling liberal blaming Hitler on the US.
Japan had already beaten China and was running the French and British out Asia. We were their only obstacle. The idea that we had this massive technology gap is laughable and shows how far you have to go support your ideals. We had superior manufacturing which in the end seeing the war but at the start they had better planes and midway they were kicking our ass across the Atlantic.
If you imagination it's to limited to understand what the world would look like with out US I can't help you
But you really should stop claim to a conservative.