This makes any libertarian government at least potentially imperialist, but very few understand that. Sh-h.
There's nothing "imperial" about doing that. Where you'll run into trouble is trying to establish or manipulate the government of that country to your own perceived needs while or after you "get" the perpetrator[s] and there's nothing libertarian about that.
National soverignty is not a statist construct. It is an extension of your own personal liberty and soveriegnty.
If national soverignty is a statist construct then so is freedom.
I strongly disagree. A common defense, the rule of law, and enforcement of the right of contract are national issues and identify "empire". National sovereignty and respect of the sovereignty of other nations or cultures is fundamentally libertarian. In Libertarian Government, the strength of the USA "empire" is our commerce in cooperation with private citizens in other governments. Empire is also defined by the strength of your nation to defend itself against all enemies foreign and domestic. Such defense is the primary, if not only, federal commission.
National Sovereignty in a Libertarian Republic would be a matter of property rights agreed on by Constitutional Contract. Not a statist construct.