U.S. President Barack Obama and first lady Michelle Obama walk with Ireland’s President Mary McAleese and husband Martin McAleese before a tree planting ceremony in Dublin, Ireland, Monday, May 23, 2011.President Barack Obama opens a six-day European tour with a quick dash through Ireland, where he will celebrate his own Irish roots and look to give a boost to a nation grappling with the fallout from its financial collapse. (AP Photo/Charles Dharapak)