Irish President Mary McAleese (2nd R) and her husband Martin McAleese (R) greet US President Barack Obama (L) and his wife Michelle (2nd L) at the Presidential Residence, in Dublin, Ireland, on May 23, 2011. US President Barack Obama landed in Ireland on Monday for a visit celebrating his ancestral roots, kicking off a four-nation European tour. AFP PHOTO / NICHOLAS KAMM (Photo credit should read NICHOLAS KAMM/AFP/Getty Images)