When I first went to Hiroshima in 1967, the shadow on the steps was still there. It was an almost perfect impression of a human being at ease: legs splayed, back bent, one hand by her side as she sat waiting for a bank to open. At a quarter past eight on the morning of 6 August, 1945, she and her silhouette were burned into the granite. I stared at the shadow for an hour or more, unforgettably. When I returned many years later, it was gone: taken away, ‘disappeared’, a political embarrassment.