WASHINGTON, DC – MARCH 14: (AFP OUT) U.S. President Barack Obama (R), first lady Michelle Obama (2nd L), British Prime Minister David Cameron (3rd L) and his wife Samantha Cameron (L) pose for an official photo at the Grand Staircase of the White House March 14, 2012 in Washington, DC. Prime Minister Cameron was on a three-day visit in the U.S. and he had talks with President Obama earlier the day. (Photo by Alex Wong/Getty Images)