All bloody principles and practices we do utterly deny, with all outward wars, and strife, and fightings with outward weapons, for any end, or under any pretence whatsoever, and this is our testimony to the whole world. That spirit of Christ by which we are guided is not changeable, so as once to command us from a thing as evil and again to move unto it; and we do certainly know, and so testify to the world, that the spirit of Christ, which leads us into all Truth, will never move us to fight any war against any man with outward weapons, neither for the kingdom of Christ, nor for the kingdoms of this world.
-- Quaker “Peace Testimony”, 1660
This has not been un-controversial, even among the first generation of Quakers. Isaac Penington, for instance, held that the State had a duty to protect innocents, using force if necessary.
Further difficulty has surrounded the permissibility of paying taxes to support a government which does not practice pacifist principles. To this day, some American Quakers refuse to pay that portion of their Federal taxes which goes to support the military, sometimes facing prosecution or asset forfeiture; others contribute money to escrow accounts, run by Quaker associations, which the Internal Revenue Service can only access upon condition that the money be used for non-military purposes.