Tu? Si vous voulez.
Daniel Johnson looks at the importance of formal language in France and Germany and the growing use of "tu" in France. An excerpt:
Tu or vous? Du or Sie? In English, the second person singular has long since ceased to be a source of political controversy—though in the days when Quakers insisted on calling their social superiors “Thee” and “Thou,” it mattered very much. In French and German, it still matters.
Newly elected French President Nicolas Sarkozy raised eyebrows in Berlin last week on his first official visit by presuming to tutoie Angela Merkel, the German Chancellor: “Chère Angela . . . J’ai confiance en toi.” (Dear Angela . . . I have confidence in you.) Frau Merkel, who addressed him as “Lieber Nicolas” (Dear Nicolas), responded with the formal Sie, at least in public. The French press noted the disparity and gently mocked Mr. Sarkozy—though not nearly as harshly as they did Tony Blair. Blair once dared to tutoie Jacques Chirac, who liked to stand on his dignity as a head of state, deserving deference from mere heads of government. The British prime minister was firmly put in his place. What sounded to British ears like Mr. Chirac’s pomposity was, however, approved of by the French. His Socialist predecessor François Mitterrand was once asked if he would mind if he were addressed as tu: “Si vous voulez” was his reply.