Things like the Invasion of the Body Snatchers and alien abduction in general (especially when abductees are subjected to mind-control or brainwashing, usuall through neural implants) is a sublimation of fear of foreign infiltration.

It is not a coincidence that these genres have their heyday at the peak of cold-war paranoia in the US in the 1950's.

Most economists teach a theoretical framework that has been shown to be fundamentally useless. -- James K. Galbraith