Part of the subtle brilliance of Threads is how it deliberately withholds information from you. You do NOT learn the fate of many of the characters. Including--

Part of the subtle brilliance of Threads is how it deliberately withholds information from you. You do NOT learn the fate of many of the characters. Including---spoiler alert---the character you initially THINK is the main protagonist, until halfway through the film when he disappears with never another trace. You do NOT learn the fate of the rest of the world besides the UK. All of this is brilliant because the characters themselves would also never learn those things.