Earlier quoted context omitted.
All governments, regardless of their nature, all civil societies and all bodies of law, from the hardest fascist dictatorships to the freest democracies, claim legitimacy by and execute enforcement through a monopoly on violence. Pretending the US is any different in this regard is silly.
govt in the US does not have a monopoly on violence... they want you to think they do ;)
It doesn't mean the government is the only agent capable of committing violence, rather, that the government determines what forms of violence, and under what circumstances, are legal, and that the enforcement of laws and contracts are always backed up by an implicit threat of violence through incarceration or worse.
The Second Amendment being legal doctrine adopted by the government is an example of that monopoly being extended to the people - yet the same government that passed the Second Amendment also put down Shay's Rebellion. That's the monopoly on violence.