One of the reason of the rise to superpower status of the United States was the power vacuum left by the devastation of Europe and Asia industrial base during WWII and the help that this war had in pulling America out of the 30's economic quagmire.
What if WWII had never happened in Europe as in France and England decisively reoccupying the Rhineland after the Austrian annexation. This causes fear in the Germans mind that it will lead to another major war helping bring down Hitler and the Nazi party (with or without help of the German army). A war with Japan would still happen but the outcome would make America a major naval power but not much else.
Considering no Lend-Lease, no funnelling of the unemployed in the army, no massive arsenal buildup, no european immigration, no cold war, german, french, english and italian industry in much better shape, a continuing recession and lingering isolationist mood; would the United States still become THE economic and military superpower of the day or just a major power? What would be its effect on the rest of history?