When did the USA try isolationism and have it not work. If you refer to WWI and WWII, the USA was hardly isolationist in either of those conflicts. Between the embargoing of Japan in WWII (which was reasonable, and Japan's attack on pearl harbor very stupid), and US ships following German U-boats and broadcasting locations, they were hardly impartial. In WWI the Lusitania was actually found to be carrying weapons. The US has not done real isolationism.
Pearl Harbor, 9/11. If you'd argue limiting oil exports to the empire of Japan or arming the Mujahideen (1) aren't isolationist policies and (2) caused those attacks, consider that your definition of isolationism might require the US to give up its sovereignty.
And there it is, the "no true isolationist" argument. It's always disappointing to see arguments about major policy issues on HN descend into this type of low-effort "gotcha" while entirely missing the main point.
If everything short of boots on the ground is Isolationism, then nothing is. These are definitionally non-isolationist things that were being done despite the populace at the time being isolationist.
