We nevered declared war on North Vietnam, and the UN didn't authorize it.
No, I was mainly speaking about the Romans, a subject raised by a_Pole. They were pretty fanatical about going through all the proper rituals of declaring war.
My chief objection to clinton's war with Yugoslavia is that it was fought on the wrong side, and with totally unreal multicultural expectations that all the factions would get along once they were instructed in the ideals of the New World Order.