All over a governments abilities boil down in their extreme to their monopoly on violence.
Most people's decisions whether to follow or disobey laws are more heavily influenced by social pressures and conventions than the fear of imprisonment or physical assault by cops.
Incidentally, what usually happens when you don't pay taxes is you get nasty letters. If you have wages they might be garnished, and if you have assets they may be seized. Employers comply with garnishments and banks comply with seizures mostly for social reasons, not because of a fear that they will be imprisoned or shot for selflessly protecting a deadbeat.
A reasonable thought experiment is to imagine what would happen if the government convincingly announced that it would no longer perform any physical enforcement of any laws. I for one wouldn't immediately go out and murder or burgle anyone, because my reasons for not doing those things are firstly my ethical intuition that such an act is wrong and secondly the fact that people are likely to fight back. But you better believe that I would immediately disregard some laws, particularly ones prohibiting so-called victimless crimes.
I would make essentially the exact opposite argument as you. I think that most people believe that government is not primarily in power because of violence, I think they're wrong, and I think history (ancient to modern) makes it extremely clear that they're wrong.
Governments that rely on violence may be perceived as legitimate by force but they frequently lack credibility.
Locke's _Two Treatises of Government_ is one of the earlier sources for this model, but it's a common theme in liberal political theory.
Not that I inherently oppose the use of violence to ensure that certain things that society has agreed on are enforced,
Just that in many cases, I believe I would follow a current law set by a government even if there was no chance of punishment by the government (other than perhaps a public record)
(This is not to say that this is true of the majority of a given population, just that I believe that it is probably true about some people because I think it is probably true about me. (though I of course could be wrong in how I model myself) )
Note that I am claiming that there exist laws that I would follow without enforcement, but would not follow if they were not laws,
but I am /not/ claiming that, for all laws, whether or not I follow said law is not affected by whether it is enforced.
Try seizing houses from people without the threat of guns and violence, see how that works out.
What possible motivation would employers have to shelter a lawbreaking employee, at no benefit to themselves? Why would the threat of violence be remotely necessary?
What makes you think that? As far as I know, there is no easy way for a third party to determine whether any given company cooperates with garnishment orders, so how can this incentive exist?
> and because they have accepted the proposition that paying a reasonable amount of tax is a civic duty.
I imagine that most citizens think some level of taxation is a civic duty. But I also suspect that a large portion of citizens think their own level of taxation is too high, and would give less to the government if the government changed its rule to "give us whatever you think is appropriate to fulfill your civic duty."
I like this definition better because it avoids some of the objections people have responded with. 1) it avoids the word "violence" - the use of force does not require violence, and I think most people would hope that governments wouldn't use violence in their enforcement of laws (though we know that in practice this is often not the case), though the threat of force is more consistently necessary) and 2) it acknowledges that it's not a monopoly on the use of force, as the reality is that many people use force, but on its legitimate use.
I know it's even called "monopoly on violence" in the wikipedia article, so it's not that I think you're mistaken, but rather I prefer this definition. The article mentions the term "monopoly on violence" in English is indeed common, but also controversial.