Mr Prager's choice of municiple policeman is a terrible example. Where do the policeman of Pittsburg get their authority to patrol and arrest criminals? From the consent of the governed. The salary of the cops is paid for by the tax dollars of Pittsburg citizens and the city charter allows policeman to keep the peace. In other words, this is a relation of choice.
Where does America get it authority to keep recalcitrant nations in line? From where comes its authority to bomb errant countries? Have any countries agreed to this authority? Are any paying America to do this job?
This is a complex issue, I agree. I don't know the best course of action. But to compare it to a domestic police force is the worst possible example.