You don't have to imagine all this from a movie. How was Europe and Asia after WW II not apocalyptic? The Red Army in Germany in 1945 raped hundreds of thousands of women, stole everything that wasn't nailed down including whole factories, shot people at will, and dragged any man they even suspected of having been in the Wehrmacht to Siberia to be a slave. They might as well have been zombies. Even the countries where there was some order imposed by the invading Allied armies, everything was bombed flat or mined including the water systems, railroads, bridges, and electrical grid. Highways and airports were cratered and ports were full of mines and sunken ships. There were millions of POWs, released POWs, and displaced people with nowhere to go. There was mass starvation, rampant diesase, and criminals operated at will. Women would prostitute themselves for a pack of cigarettes. Some of Europe and all of Japan were still being run by fascist bureaucrats, some of whom would be hanged. There was no school, or hospital, or a store with anything in it. The police burned their uniforms. There were millions of crippled people, especially young men, and the unburied dead. There were whole bombed cities full of people with PTSD. The suicide rate was off the chart, but no one was counting. As for the Axis countries, the horrors they were engaged in were laid bare. They looked like monsters.

That was 75 years ago, but Europe and Japan left the wasteland phase over fifty years ago, and are now wonderful places to live and visit. They were helped by the USA by the way.