However, in my country, where we use FPTP, we have frequently got extremist parties in power. If seats had been given proportionally, they might not have got power, or would have to operate in Big Tent coalitions. In the last general election, 486(!) parties fielded candidates. Of course, most of them would not reach the threshold for representation in PR. But some of them will. That would almost always cause hung parliaments. Upside is, minorities like Muslims will get better representation. They are heavily underrepresented in legislatures due to their dispersal.

IRV has the problem that (a) many votes would get exhausted. However, if to control for that you impose a minimum number of choices, you would get a higher number of invalid votes. Or even donkey voting - just filling out at random. Score voting, in my opinion, better captures the reality of human preference.

So, if you had to choose an election system for USA, what would you choose?

The 1953 Iranian coup strengthened the Iranian monarchy and overthrew Mossadegh the Prime Minister. And Britain would have got Mossadegh out anyway - they were fighting on the ownership of oil installations. If a British-backed coup ended up failing, Iran would probably have been pushed into the arms of Soviet Union. (Just like Nasser in Egypt after the Suez crisis) We could have ended up with an Arab conquest of Israel - if Iran allowed Soviet forces to move into Soviet-leaning Iraq and Syria in 1967.

What voting method in your opinion is superior to single-member district plurality election with one vote per voter? Ranked Choice Voting, Approval Voting, Score Voting?

Mongol conquests happened in China, Central Asia, Iran, East Europe etc. It was a number of different wars over a long period of time.

If a nuclear war happened, say, in 1983, what percent of people would die?

Taking the pandemic seriously was not local to the rationalist community. Many people, including my father, began to take the pandemic seriously in late January. He avoided any major travel, and largely remained at home. He began to wear masks from early March, when cases were few. This is in India, not USA.

I agree. Some intellectuals in the West could not even condemn the execution of Lenin's comrades by Stalin on trumped up charges. I will trust no Sovietologist who tries to show that Stalin was a good person.