But wasn't this mostly based on the armaments bubble that Nazi policies had created?
The output was, but the industrial potential was there provided they could find a market for it, which given how much they owed others and the looming deal with the Soviets should have been possible to manage and expand over time. The Depression was ending and global trade picking up despite the Japanese war in the East provided the Nazi leadership understood war was not going to end well for them, which Goering seemed to get, though he did favor war in the long run; of course as we know the long run would have turned the odds even more against Germany and made it impossible to start with any hope of victory, so its likely that a Goering led Germany would ultimately demure in the end.