>In a society primarily driven by voluntary exchange and interactions
If you can make such a society real, than please sign me up.
>To me this appears to undermine the principles of a liberal democracy founded on self-determination and individual sovereignty,
It really doesn't mean shit if a Coca-Cola™ militia is allowed to kill labor leaders in Colombia without reprimand, unless you argue that the labor leaders were in a one sided voluntary exchange of bullets with Coca-Cola. This is the normal state of affairs since day 1 of liberal capitalism btw. Capitalism has been enforced since forever via violent means. Better off countries that support themselves on the backs of third world labor might not have had it so bad, but even then, google any country together with "violent protest" to see Capital enforce itself, non-voluntarily, onto the people. Worse off countries, I'm sure you know, get fucked by a myriad of things, but are basically kept poor, violent, and corrupt, for profit purposes.