Preventive Diplomacy at the UNThe concept of preventive diplomacy has captivated the United Nations since it was first articulated by Secretary General Dag Hammarskjld a half century ago. Successive generations of diplomats and statesmen have invested in the idea that diplomatic efforts might be able to head off international conflicts and disasters. Dramatic successes, such as the Cuban Missile Crisis of 1962, contrast with dramatic failures, such as the inability of UN efforts