This is story where the human race, once widespread in the galaxy, was beaten back to our home planet after a devastating interstellar war. The aliens won the war and the Moon -- an artificial monitoring station -- was moved into orbit around the Earth to ensure that humanity would stay put, by a final treaty. (Yeah, I know, even as a kid I thought the Moon was improbably large and massive for this purpose.) Our species collapsed into barbarism but the aliens kept their end of the bargain and simply continued to watch across the millennia. The cartoon included a picture of the Moon being moved into place; craters were rendered as the outward part of hidden sensing devices. Can this tale be identified?
There was also a Matheson-like short story with a very similar plot, but that is a different question. The comic book, almost certainly American, appeared in English in the 1950s or 60s.