It doesn't seem like aliens need to be involved for the song's story. I always took it as a nuclear holocaust because the food is mostly bad, I assume irradiated. Also, post-apocalyptic because sailboats need no petrol or other supportive civilization for travel. They can just go with the wind. And the common belief back then was that in a nuclear war there would be no winners, just precious few survivors.
It doesn't seem like aliens need to be involved for the song's story. I always took it as a nuclear holocaust because the food is mostly bad, I assume irradiated. Also, post-apocalyptic because sailboats need no petrol or other supportive civilization for travel. They can just go with the wind. And the common belief back then was that in a nuclear war there would be no winners, just precious few survivors.