WTF?
Americans scream that there can be no civil war without financing, but how can terrorists fight the US in Afghanistan?
How did Vietnam defeat the USA?
When was the last time that the US won a war?
How did the Americans defeat the British?
https://www.quora.com/Who-financed-the-American-Revolution
How did the rebels fight the US in the first Civil War?
https://www.quora.com/How-did-the-South-finance-the-Civil-War
https://www.essentialcivilwarcurriculum.com/financing-the-civil-war.html
Do Americans have guns?
Can American rebels seize military bases and gun factories?
Can foreign governments arm American patriots?
@dcjogger Vietnam didn't defeat the USA though. It was the USA who defeated the USA in Vietnam war.
And of course in all the examples you've mentioned there was financial and military support from other countries. Now, I'm sure a lot of countries would gladly finance civil war in the US, but they'd probably support groups that are at least to some degree socialist, national-socialist, religious socialist etc. Why would they support libertarians? If libertarians would have their way in the US, it would become the world's most free and most prosperous country, and then their own people would desire liberty as well.