The basic idea is that a first world AI came alive and just shuts things down to ensure victory. No massive wars but a lot of people died cause the AI offers comfort, safety, and rather good lives in exchange for surrender.
Germany makes a nuclear bomb and shows it off. Peace terms reached, barely but say a total miracle happened in Hitler/Nazi commanders have some high altitude jet bomber. As it is fanciful to a degree I see it like a nuke going off in Iceland and Leningrad. But even then... America will get the...