Image of the week: Look back, face forward

US president Barack Obama, right, and Japanese prime minister Shinzo Abe speak while looking at the Atomic Bomb Dome in the Hiroshima Peace Memorial Park in Hiroshima, western Japan, last weekend. The dome is the only major building left partially standing after the American military dropped the first atomic bomb on the city on 6 August, 1945. On Friday Obama became the first sitting US president to visit the city since the attack, bringing global attention both to survivors and to his vision of a world without nuclear weapons.