As others have pointed out Russia didn't have high-speed rail. The reason is related to the real reason the US doesn't have it. It's of course density. Relevant

As others have pointed out Russia didn't have high-speed rail. The reason is related to the real reason the US doesn't have it. It's of course density. Relevant US cities are much further apart. You practically need hsr to make it practical at all which prevents incremental improvement of the train system. I hear that's different on the east coast (I've spent very little time there) but it certainly sets culture when for most of the country trains are a bad option.