i doubt America would back that since at that point twitter is doing nothing illegal here. just refusing to block eu citizens. similar to how extradition generally requires something being a crime in both countries.

Not blocking certain users in a jurisdiction where these blocks are required by law is, by definition, illegal. Obviously, some countries have more power to enforce those things than others. Also obviously, the EU is among the front runners of power to be able to enforce those things. And I am fairly sure the US won't start a trade war over Twitter the way the EU and the US did over Airbus and Boeing.

no it's not, because the internet doesn't require you to be present in some place so you are not subject to that jurisdiction. i do not recognize the jurisdiction of a country to demand a block of its citizens from a company located in an entirely different nation, and i doubt American courts would either.

like imagine i host a human rights site. if iran says it is illegal for me to provide access to content supporting womens rights to iranian citizens, it is not "illegal" for me to continue doing so because i am American, i live in America, and i operate only by American laws. America would not extradite me to iran for failing to comply with their internet rules.

Fair enough, unless you choose to operate in, e.g., Iran. Now you have options:

1) follow Iranian law

2a) not follow Iranian law and be blocked

2c) not follow Iranian law, circumvent any blocking and be prosecuted

2c obviously wont matter much in the case of Iran, in other cases it might. And while the US wont extradite you, other countries might. And there is still the option of abusing Interpol and red notices, again maybe not a problem in case of Iran and US internet co executives.

You know who thought the same way you do? German citizen living in NZ Kim Dotcom. You know who disagreed? The US DoJ. Would be about time if other countries would do the same to certain US entities, wouldn't it?

See : the spying allegation issues by the US against a French CEO of Alstom. He went straight to jail.

It’s fairly commonly recognized it’s was a ploy to force the sell of Alstom to GE, as opposed to a Chinese joint venture

No; that was the US does. See Alstom French CEO jailed in the US because he wanted to sell to Chinese and not GE.