LONDON, ENGLAND – MAY 24: US President Barack Obama reviews an honour guard with Prince Philip, Duke of Edinburgh (R) at Buckingham Palace on May 24, 2011 in London, England. The 44th President of the United States, Barack Obama, and his wife Michelle are in the UK for a two day State Visit at the invitation of HM Queen Elizabeth II. During the trip they will attend a state banquet at Buckingham Palace and the President will address both houses of parliament at Westminster Hall. (Photo by Toby Melville – WPA Pool/Getty Images)