US President Barack Obama (R) pays hios respects at the Tomb of the Unknown Soldier in Warsaw on May 27, 2011. US President Barack Obama arrived in Poland today for a summit with leaders of ex-communist nations on the lessons of their decades of reform for the Arab Spring, with Belarus singled out as a transition gone wrong. AFP PHOTO / Jewel Samad (Photo credit should read JEWEL SAMAD/AFP/Getty Images)