These are all interesting examples, but they support the point rather than deny it. If you have an inferior force, usually you get invaded (see Ukraine). Even paying can still be done to support your opposition until they control the government (see banana republics). Either way, you no longer hold the monopoly on violence, somebody else does.
Guns and MAD are exactly the kind of violence society is founded upon. Ultimately you can't just stop paying tax or start driving illegal vehicles, because the state (usually) has a bigger gun than you. (In the case where it doesn't, you end up with something like Somalia or the mafia). MAD is the ultimate gun, not the absence of gun.
A doctor might be willing to die, but every man has a price he is not willing to pay - whether that's his child or a random child you pick off the street and make violent threats towards.
Payment is just a disguise and a convenience - the underlying order is still based on violence.