[MISES] In history classes (in public or private schools, colleges, and others), state propaganda, and mainstream history, a historical fiction has been spun that allegedly debunks any notion of noninterventionism. This is the myth of American isolationism.The assertion usually goes that America was extremely isolationist prior to World War I and had no interest in involving itself in unnecessary warfare. After the Zimmermann telegram was sent, America was then forced to enter the war, quickly ended the war, and promptly withdrew from meddling with the outside world, even refusing to enter the League of Nations. America then spent the next two decades in isolation, foolishly ignoring the world stage until being unexpectedly attacked by Japan.
Variations exist, but this is the general reasoning pushed by the State Department, the Council on Foreign Relations, and Wikipedia. I also distinctly remember hearing that line of reasoning in multiple history classes going back to when I was in the seventh grade.
The MISES graphic is telling.