Well, the other issue being foreign countries with government-funded militaries are unlikely to just ignore you and permanently suspend travel and diplomatic re

Well, the other issue being foreign countries with government-funded militaries are unlikely to just ignore you and permanently suspend travel and diplomatic relations, and as soon as their citizens are facing threats in your paradise, those foreign militaries are likely to get involved. Major coordination problem in that ancap paradise probably only works if everyone does it.^[1] At least the communist version of utopia acknowledged this with Comintern (doomed to fail for other reasons, of course). [1] Editing to add the note, in case David Friedman comes in here talking about medieval Iceland, I guess it can also work if the world does not yet have widespread global travel and expeditionary militaries.