Since we like old Sci-Fi, we watched Things to Come (1936). It was based on a, H.G. Wells treatment of his story The Shape of Things to Come. Not that great as science or fiction, but great science fiction.
It starts around Christmas in Everytown, England. Raymond Massey is worried about rumors of war in the news, but his obtuse friend Edward Chapman tells him it's probably nothing. Then the bombs start falling. It doesn't take a prophet to predict, in 1936, that war is coming, but he got that right.
The movie is pretty episodic, skipping through future history, always meeting thoughtful Massey and feckless Chapman. The war continues for years, leaving Everytown (basically, London) a ruin. A strongman, Ralph Richardson, rules the neighborhood, dreaming of the day when he can get an airplane flying to defeat the hill people and steal their coal.
But there is a nascent World Government of scientists called "Wings over the World" that is bringing civilization back, and Massey is their vanguard.
The politics is a bit suspect - technocratic fascism? - the story is a little choppy and the writing is no better than it needs to be. So is it worth watching? I'd say yes, mainly for the costumes and sets. Once again, art direction FTW.