From all-out war to vulnerable pairs of military observers in blue berets, the United Nations Security Council can authorize a full spectrum of intervention.  Observers, peacekeepers, peacemakers – the terms vary as do the mandates. And there is plenty of overlap. Outcomes vary, too.  Some UN missions, such as the traditional buffer-zone peacekeepers still patrolling a “Green Line” in Cyprus after a half-century, seem to become part of an imperfect solution.