The term “monopoly on violence” (alternately “monopoly on physical force”) is an ominous one that understandably conjures up images of police beating protesters. However, what it really describes is the state’s general ability to impose coercive consequences for breaking the law*. That can include physical main force but more commonly involves things like fines or prison time for not paying taxes. Obviously, any of those measures can be abused or disproportionately directed at certain groups.
To be clear, that isn’t an argument that “tax is theft” in the way Libertarians describe it. If we live in a society, there has to be some way of ensuring that we behave according to its rules. The concept of the nation-state’s “monopoly on violence” basically gives its agents license to do what ordinary citizens cannot, one hopes within a constitutional framework that prioritises the human rights of all classes of citizens over the state’s right to do whatever it wants.
Anarchists will disagree that this is workable, but they’ll do it in a more nuanced way that the “free”-market fundie with his limited “I’ve got mine, Jack” concerns and his simple-minded talking points.
[* the real question is whether the law being enforced is just]
