A hard-won national dialogue between Tunisia\'s ruling Islamists and the opposition to end a major political crisis began Friday after repeated delays, the lead mediator which brokered the talks said. \"Today is an important date in the history of Tunisia. The whole world is watching and waiting for us to succeed,\" the powerful UGTT trade union said on its Facebook page. \"We have registered our first success with the official launch of the national dialogue,\" it quoted UGTT chief Houcine Abassi as saying at the start of the closed-door negotiations.