US President Barack Obama (FarC) walks flanked by Irish President Mary McAleese (FarR) and her husband Martin McAleese (FarL) as they arrive at the President’s Residence to plant a tree in Dublin on May 23, 2011. Obama landed in Ireland on May 23, 2011 for a visit celebrating his ancestral roots, kicking off a four-nation European tour. AFP PHOTO/ JEWEL SAMAD (Photo credit should read JEWEL SAMAD/AFP/Getty Images)