It seems entirely possible according to modern thought on quantum physics that even if the world was annihilated in a nuclear war we might continue to exist in a different dimension. Given this theory of different possible lives all progressing concurrently we might not even notice the destruction. That particular time-line would be left to clean up that ungodly mess while another time line would be free to live as if nothing ever happened. So, although there may have been a horrific nuclear disaster/war in 1974 a fresh copy of the Earth and everything on it would be allowed to simply skip along free of even the memory of such devastation. Live on. Live Strong. We are but a dream.