As a kid I remember learning that the atomic bombs contributed to Japan's surrender in WW2, but as a grown-up I also learned that Russia (a neighboring country) declared war on Japan two days after the first bomb was dropped, and I wonder which made more of a difference.

https://en.wikipedia.org/wiki/Soviet%E2%80%93Japanese_War_(1...

The US government did a lot of things to affect the way communism was viewed in the US, so I suspect there may have been some official spin involved here.