Summary
TheFalloutshow answers one of the longest-running questions in the series, finally telling us who dropped the bombs first. The answer goes against what the creator of the series, Tim Cain,revealed just last year, and is dividing fans of the games.
Huge spoilers for the Fallout finale ahead.
It turns out that it wasn’t the US or China who started the Great War - it was Vault-Tec. That might be an oversimplification - the US was the one who funded Vault-Tec, after all - but the show makes it clear that it was they who dropped the nukes first, turning the world into an irradiated wasteland.
The reveal comes at the very end of Fallout’s first season, during a flashback. Here, we see a meeting between Vault-Tec and the heads of various US-based corporations,including Mr. House. Vault-Tec offers these companies the chance to invest in the vaults, which also lets them decide how they’ll be run, explaining the strange experiments we uncover in the games.

Unsurprisingly, some are unwilling to put money behind a project that will only pan out if the bombs drop, which isn’t guaranteed. But Vault-Tec have planned for this, and reveal that they’ll be the one to drop the bombs after all.
This Isn’t The First Attempt To Reveal Who Dropped The Bombs In Fallout
Fans appear to be split on this explanation, which is understandable, given how long this question concerning the Great War went unanswered. However, if things had panned out differently, this may have been the answer we were given years ago, as this is very close to the reveal that was set to take place in the cancelled Fallout movie. As per theunearthed film treatmentfor the scrapped Fallout movie:
The first nuclear bomb was launched by the creator of the vaults, a zealot businessman who wanted to fulfill his own prophecy of world annihilation. That first bomb triggered a panicked chain reaction among other countries, leading to a four hour WWIII.
With that said, series creator Tim Cain had other ideas. Last year, he revealed that in his mind, it was China who launched the first nuke, in response to discovering that the US was working on the Forced Evolutionary Virus (FEV). At the very least,Cain is enjoying the Fallout show so far, having attended the premiere ahead of its release. Hopefully, this doesn’t ruin it for him.