US President Barack Obama delivers remarks at the dedication ceremony for the George W. Bush Presidential Center in Dallas, April 25, 2013. Obama is in Texas to stand shoulder-to-shoulder with former president George W. Bush in what could serve as a powerful reminder of the ongoing struggle against terrorism, from the Sept 11 attacks to the Boston Marathon bombings. Also pictured are former first ladies Barbara (2nd L) and Laura Bush (R) and former presidents George H.W. Bush and George W. Bush (2nd R).[Photo/Agencies]