WASHINGTON, (AP) -- The White House reacted cautiously on Thursday to the narrow third-term victory of British Prime Minister Tony Blair, President Bush's staunchest Iraq war ally. Blair's Labour Party won in Britain's national elections, but exit poll projections indicated his party suffered a sharply reduced parliamentary majority, an apparent rebuke for going to war in Iraq. Bush, who was leaving Friday for a four-country, five-day tour of eastern and central Europe, was expected call to Blair to congratulate him on the narrow victory, White House aides said. Commenting on the lackluster returns, a chastened Blair said, "We will have...