https://en.wikipedia.org/wiki/Allied_intervention_in_the_Russian_Civil_War
You mean this one? Technically the USA were invited in like vampires by the current official ruler technically to fight rebellion. So “attacked” - no. Sold itself like a mercenary imperialistic scum in some deal to a despotic tsar - definitely.
Oh, and they were barely USian soldiers, it was mostly Europeans. And to be perfectly candid, everything about that intervention is considered to be British brainchild - look at the Korniłow and the support he got from Britain until he failed.
At least that’s my take on it.










Ancient Greek democracy begs to differ https://en.wikipedia.org/wiki/Sortition
They argued that electoralism will result in rich amd artistocracy corrupting the whole process and getting into power and never letting it go, focusing on their own selfish interests