WWII? I think people really believed that Japan had ambitions to invade and occupy the US. Maybe Russia to some degree in the Cold War era, but I think the greatest fear was due to the threat of nuclear war/Armageddon, not boots on the ground land invasion.
So there hasn't been a credible threat of invasion in ~40-70 years, the US spends more on military expenditures than the rest of the world combined and the masses still think the our armed forces are 'defending' the US from freedom-destroying dictators invading from foreign lands??!?
So there hasn't been a credible threat of invasion in ~40-70 years, the US spends more on military expenditures than the rest of the world combined and the masses still think the our armed forces are 'defending' the US from freedom-destroying dictators invading from foreign lands??!?