All four of his grandparents were children of Irish immigrants. Kennedy had an elder brother, Joseph Jr., and seven younger siblings: Rosemary, Kathleen ('Kick'), Eunice, Patricia, Robert ('Bobby'), Jean, and Edward ('Ted'). Sorensen added that, in his opinion, Vietnam 'was the only foreign policy problem handed off by JFK to his successor in no better, and possibly worse, shape than it was when he inherited it.' U.S. involvement in the region escalated until his successor Lyndon Johnson directly deployed regular U.S. military forces for fighting the Vietnam War.