I'm tempted to embrace isolationism, but I'm always reminded of the nagging fact that stubborn isolationism is what kept the U.S out of WW2 for so long. Nazi Germany conquered most of Europe and we didn't do anything aside from loaning out supplies and providing a few naval escorts. We're lucky that the U.K and USSR were able to pull their weight until the U.S received it's wake up call at Pearl Harbor.
Stubborn isolationism? America was profiting big time from military industry, loaning (even more profitable than selling) and selling stuff to mainly Britain, but all over Europe, along with continually provoking Japan to war, and when it finally did get into the Pacific War, it was even better for America- the propaganda drew Pearl Harbour as if it was a full surprise, but "the American folk must go on". Also, Britain was very able to "hold its weight" for a very long time, the Germans had no chance at invading the island with modern British air defence systems and an insufficient navy, and so started a (perhaps unwinable, from all the American resources) attrition war. As for Russia, well, it was doing more than "holding its weight", and American supplies did not significantly help, too few and poor.
I could hold what you're saying if you talked about Japan and China, but you aren't - and furthermore, pragmatic politics by this time dominated everywhere.
