Values and Weapons looks at the determinants of legitimacy for using military force in the US and Europe. The non-intervention norm is weakened by the advent of terror groups in failed states as well as by so-called humanitarian intervention. The development of a norm that calls for a 'duty to protect' has paved the way for intervention also into so-called 'failed' states. Sovereignty has been redefined to be conditional on democratic government, and this makes it much easier to intervene into non-democratic states.