The United States should have intervened in WWII by 1939 in order to stop the spread of communism, prevent human rights violations, and encourage economic prosperity.
The U.S. was a safe haven for many Jews on the run from Hitler’s tyranny in Europe. Despite it’s seemingly accepting border patrol, there was a boom of anti-semitism in the United States during WWII. No one knows for sure when the U.S. government found out about the atrocities committed against different races in Europe in the late 1930’s. There is a conspiracy that FDR and his cabinet had some knowledge of Hitler’s crimes against the Jewish people but turned the other way until 1941 when we were attacked on U.S. soil.