Outgoing Senate Majority Leader George Mitchell is headed to Ireland and its comparatively less hostile shores (at least compared with the current congressional climate). President Clinton today appointed Mitchell as a special adviser to promote trade and investment in Northern Ireland. Mitchell, a descendent of Irish immigrants, said the appointment "means a great deal to me." He'll take the post on January 10. One of his first tasks will be to oversee a White House conference on trade and investment in Northern Ireland -- to be held in Philadelphia in April.Post your opinion on theInternationalbulletin board.