This year, for the first time since 1945, the US ambassador to Japan attended the annual commemoration of the atomic bombing of Hiroshima. Should President Obama make a visit? Should the US apologize? What are the effects of nuclear radiation? We hear from Dr. James Yamazaki, the lead physician of the US Atomic Bomb Medical Team which surveyed the effects of the bomb on Nagazaki, and from Tsuyoshi Hasegawa, Professor of History at the University of California at Santa Barbara.