Pacificism is the general ethical opposition to violence or war, except in cases where force is deemed absolutely necessary to advance the cause of peace. It falls between pacifism, which usually states that killing, violence or war is unconditionally wrong in all cases, and defensivism, which accepts all defensive wars and acts of deterrence as morally just. Pacificism states that war can only ever be considered as a firm "last resort", condemning both aggression and militarism.