Blair's Man in Brussels

British M.P. and former Cabinet Minister Peter Mandelson has a lot of enemies, but he has one very old and dear friend: Prime Minister Tony Blair, who last week named him the U.K.'s representative on the European Commission. Of Mandelson's talents and aptitude for the job there is little doubt. He is one of the Labour Party's most passionate pro-Europeans and a principal architect of the party's 1980s makeover from an unpopular assemblage of hapless lefties to the formidable centrist vote-getting machine it became under Blair. But he is also Machiavellian and polarizing. He has had to quit the Cabinet twice,...