Four years? Counting how? War in Europe began in September 1939. So the US didn't do anything until September 1943? Bull. (I mean, I guess they didn't land in Europe until Italy, which was 1943. But even though it wasn't in Europe, they were still fighting Germany in Africa in 1942.)
> It only joined the war after Europeans had already killed more than 23 million Germans, and destroyed most of its military.
German military casualties were only 5.3 million by the high estimate. Total German casualties were only 7.4 million by the high estimate - for the whole war. So... I don't know where you get your ideas, but they are objectively very wrong.
So you agree that it took 4 years before the US entered the war in Europe. And yes I am probably wrong about the 23 million. It doesn’t change my conclusion though: the US spent 4 years on the side line selling weapons to Europe, and only joined the war after most of the German war machine was defeated.
If you consider the entire North Africa campaign to be "the sidelines" I suppose. I completely disagree with your conclusions, though, because I completely disagree that North Africa was "the sidelines", even with respect to Europe. What were they doing in North Africa? Killing Germans. Was that "selling weapons to Europe", or was it more than that? I claim that it was much more.
The entire North Africa campaign certainly was the sidelines, by any measure. It involved a tiny fraction of German forces. Every day spent in Africa was a day not spent advancing on the German heartland.
That said, the US was far from ready to advance on the German heartland until after the time they were pottering about in Africa. It was a way to look busy.
Entering the war while Germany and Russia were on the same side would have been fatal, and might even have prevented or delayed their fission.
Staying out long after the split, while Germany and Russia gored one another, was clearly the wiser course. Entering before the Soviets could subdue Germany and overrun western Europe was necessary. But any claim that the US had any sort of primary role in defeating Germany remains nonsense.
> It only joined the war after Europeans had already killed more than 23 million Germans, and destroyed most of its military.
German military casualties were only 5.3 million by the high estimate. Total German casualties were only 7.4 million by the high estimate - for the whole war. So... I don't know where you get your ideas, but they are objectively very wrong.