Mostly that sounds just funny. He can go ahead and do that.
US doesn't look kindly to someone endangering their energy supplies. Let alone territorial integrity
In fact, in Texas people make political comments about independence frequently.
In Puerto Rico, there have even been literal votes, where the people actually voted on what they want to do with this US territory, and independence was one of the options.
Further examples of these topics coming up, are the frequent comments I hear about how california, or pacific states should form up and create their own country.
And to give a more historical example, I believe a couple decades ago, there was a major Alaska independence party. This party actually even won a governorship, at one point!
People who claim that the topic of states leaving the US, is some taboo topic, that will get you sent to jail, or start a war, if people simply talk about it, are just wrong.
You are just wrong. People talk about this stuff, all the time, and there have even been official votes on this stuff. And wars aren't started over it.
It's one thing to talk between US people on various topics. Another is for head of foreign state to covertly enter your country and espouse a topic that's controversial and could cause problems for you down the line.
> And to give a more historical example
To give a more recent historical example. Election of Donald Trump. And the role Russia played. Steele dossier non-whistanding.
From what I gather, merely buying up trolls and doing some marketing was enough for US to have hissy fit, over it.