US would probably have a large impact as well, of course because lots of internet-users are from the US, but also because the US likes to astroturf as well.

tiny example: https://web.archive.org/web/20160406094911/http://www.reddit..., Most addicted city (over 100k visits total) Eglin Air Force Base, FL

let's not lose ourselves in cold-war propaganda too much and act like russians and chinese are the only ones astroturfing online.

During the Prigozhin uprising / coup attempt, internet was cut off in parts of Russia, and there was a noticeable slowdown in comments on multiple popular subreddits. I don't know if any studies have been done to evaluate this empirically though

Russia is a waning superpower with a low GDP but a powerful enough internal economy to wage a conventional invasion of a large European country. The US is a much richer country, the leading superpower, and an IT powerhouse. But for some reason the first thing that pops into people’s mind when they hear propaganda bots is “Russia”.

(I would buy China, too. A huge country with a powerful economy.)

That in itself looks like a programmed response.

Of course Russia uses bots and propaganda. But the focus on Russia seems completely out of proportion.