Elsewhere. It was chronically short of oil from the moment it launched its war effort. It had twin problems dooming it - no self sufficiency, like Japan, and governmental systems which misallocated resources.

Germany wasn’t even a country until the late 1800s. The notion of its industrial might is based on the view beginning after WW2 - the west thrived under capitalism, and unity with the rest of Western Europe. The east atrophied, like the rest of the communist world.

Our self sufficiency was not reliant on our few overseas holdings. It was barely even helped by them. Germany was kaput without its imperial holdings. Even with them - it needed more. The only country with our potential was Russia, but it had the wrong system of governance (and still does).

China is no longer in danger of overtaking American total gdp (they were never in danger on a per capita basis). It’s in decline, because Xi is fully abandoning the market reforms of his immediate predecessor.

Something that would apparently surprise you - the US was 3rd, globally, in per capita gdp as of 1900. Trailing only sparsely populated New Zealand and Australia. It was already beginning to leave Europe in its wake.