Anarcho-capitalism and minarchism are two distinct strains of libertarianism. Although anarcho-capitalists and minarchists agree on most political issues, they are sometimes hostile towards each other, particularly because most adherents of both philosophies support the non-aggression principle (NAP) and see the opposing philosophy as misrepresenting its political implications. Minarchists believe that it is the responsibility of the state to enforce NAP, while anarcho-capitalists see the state as a violation of NAP, and believe that all valuable services – including law and defense – are best provided in the marketplace.