So, it's a joke largely in the same way that democracy is a joke in the united states.
Before the KMT lost power I think it was reasonable to see Taiwan as a one party state, but no longer. You are a little ambiguous in the "two countries" do things, but I guess you mean Korea and Taiwan. Yeah, both countries are not paradises that have solved all issues, but they keep improving their freedom, industrial bases, and living standards for the average person. Is that true for the us - we should aspire to do that. Instead we have people arguing on school boards whether books that dare to discuss slavery or jim crow laws should be discussed at all. We aren't clearly moving to be a better society with that kind of stuff.
Given that this is hardly unique to the US, I think Russia is reaping the whirlwind: they've been up to this sort of thing pretty much everywhere. This is not the WWIII. They have been waging the WWIII already, this whole time, in relatively novel ways, with a lot of success… until now.
And it's been the kind of success that is short-sighted: got their way again and again at the cost of building enormous hostility, which is now rebounding upon them. Russia made this bed and all of this is not that much of a surprise, really.
The Republican Party has been the safe harbor for christian and white supremacists beginning with Reagan and the moral majority. The love of violence, "I got mine" attitudes, gleeful wastefulness, etc have been American ills long before ~2010s era Russian misinfo campaigns.
Also, speaking as an American who has had their worldview impacted by living in Europe for a while, it is beyond pathetic for liberal Americans to tell the world "Don't worry we aren't crazy! The Russians made us do the bad stuff!". As the richest country in the world, we have to take accountability.
I think more seriously the US is a limited democracy because neither party really works for the people. They both work for the donors, one just a lot more and transparent than the other.
They're terrorists because they don't want to give the government absolute power? You're doing the same thing Republicans did to Middle Eastern countries in past decades, abuse the shit out of them then call them terrorists when they try to defend themselves.