The US was playing the isolationist card until we got brought into the mess personally, but isn't that usually how things are? Didn't Canada go early on because they were part of the Empire still? The US was still needed even if it was late to the party, Churchill himself hinted in his Fight on the Beaches speech about "until, in God’s good time, the New World, with all its power and might, steps forth to the rescue and the liberation of the old."

Under the Cash‑and‑Carry and Lend‑Lease programs, Britain, the Soviet Union, China and others paid for U.S. war material largely with gold.

Those inflows swelled U.S. Treasury gold holdings from about 30 million oz in 1939 to ≈574 million oz—over half of the world’s official gold stock—by 1945.

Contemporary accounts note that by the late‑1940s the United States controlled around 70 % of global gold reserves, a figure that stemmed from wartime payments.

During this time period the US saw a reduction in unemployment by 7% and wages rose 20 to 30% pulling millions of Americans out of poverty.

The GI bill, employment act and housing act were all introduced on the back of this accrued wealth.

Of greatest impact was that these gold reserves allowed the US to set its dollar as the global reserve currency via the Breton Woods system, which led to a persistent balance of payments surplus and cheap overseas borrowing.

In simpler terms, America could borrow at the lowest interest rates since it now had the highest credit rating in the world (turns out people trust you to pay back your loans when you have 70% of the worlds gold stockpiled).

So, while I hear where you're coming from, I think it's a stretch to think there weren't politicians, industrialists and even ordinary citizens who saw that the war was rapidly improving their material circumstances (at least those that were not part of a targeted minority group). I'm sure there was fear the war would show up at their doorstep but it ultimately never did in the way Europe and other nations sustained profound infrastructure loss.

WW2 is what made the US the economic powerhouse it is today. I think that outcome alone would support that there were some, if not many, who didn't mind seeing the war go on since it worked immensely to their financial benefit.