How is the NHS very different from the military. Americans love their military and often have propaganda-style bits like fly-overs during football games. American's don't get the option to 'opt-out' of paying for its gigantic costs. Why not have military spending depend on voluntary donations?
They actually should be able to, for the most part.
The original idea of state exists to ensure 3 things:
- Protection of the territory of the state
- Protection of the integrity of the individual citizen
- Protection of the private property of the citizen
This is why people started organizing in societies and allowing the existence of a ruler class. These 3 things.
You will always need some amount of military to be part of the state. But what most countries waste today (the USA for instance), is pornographic. The state should only be allowed (by taxation) enough military to defend their territory, not to exert control over the all planet like the USA wants to do.
EDIT: Yeah, I should have guessed the part of the "integrity of the individual citizen" would, of course, be twisted. No, it's not protection of the individual from disease of from his own stupidity or lack of ability. It just means the role of the state is to ensure the citizen is protected from deliberate harm from another individual.