When I visited Hiroshima in 2003, what initially struck me was the apparent normality of the place — it seemed a busy Japanese city almost like any other. It is, and it isn’t.

A tram took me from the rail station to the Peace Park — just over the river from the ruined dome you see in so many photographs. As I sat under the trees, Japanese school students gathered my views about atomic weapons for a survey. Walking through the park you pass a grass-covered mound, two or three meters high — containing the unidentifiable ashes of some seventy thousand human beings. And to get to the park, I had walked across the unusual T-shaped bridge by the tramline from the railway station, the bridge which was the aiming point for the first atomic bomb, Little Boy, dropped on that hot summer morning in 1945.

Hiromu Morishta was seventy-three when I interviewed him, and fourteen on the day of the bombing, a patriotic student in junior high school. He and his classmates believed the statements from the military high command that Japan was winning the war, even though no one had enough to eat. His mother, starving herself to feed her children, was more sceptical. The high school students no longer attended lessons but worked in a factory making guns and aeroplane parts.

Hiromu and his friends were mystified that Hiroshima had never been bombed, since it was an important military center. Japanese cities at this time were built mainly of wood, which made them vulnerable to fire. In two days in March 1945 the Americans had dropped 2,000 tons of incendiary bombs on Tokyo — some 125,000 people had died in the worst firestorm in recorded history.

All too aware of this risk in Hiroshima, the authorities mobilized young people to tear down buildings, creating empty spaces which would have stopped the spread of fire. By 8:15 on the morning of August 6, some of them were already at work, and had stripped down to vest and shorts in the summer heat.

Hiromu and seventy of his classmates were still receiving instructions from their teachers when, he told me, “suddenly we felt — light, a flash. I felt like I had been thrown into a big furnace of fire. We fell down on the ground, but already our bodies were burned on our faces, hands, legs. The clothes were burned too.” They later realized that they had only survived because they were still fully dressed — 60 percent of the 600 or 700 students in the area had died.

Hiromu Morishta now entered a world as vivid, fragmented, and incomprehensible as a nightmare. “I jumped in the river because of the pain from the burns. In the river I met a classmate. He asked me to tell him what his face was like. I told him his face was burnt, the skin had peeled down like melted wax. I was too scared to ask what had happened to my own face, but my face had become just like his.”

The whole city had somehow been destroyed, and was now beginning to burn, but he could not understand how this was possible. He felt completely detached from what he was seeing: “I didn’t feel anything — I saw the state of the city, the houses, only my eye had become like the lens of a camera, with no feelings. We were thrown into another world.”

It was a world of horrors.

I met many young men, soldiers. They wore their uniforms, but all their skin had peeled down, they were like ghosts. I wanted to get back to my house. I walked down to Hiroshima station. I saw many people who had died: many people had jumped in the river, their bodies were burnt and they were swollen up, twice the usual size. I saw so many. It was like Hell.

People did not know that only one bomb would be dropped: they thought that there might be more to come.

Hiromu Morishta set off to find the home he shared with his parents and sister. He walked slowly along a railway track, his burnt skin hanging from him, his face so swollen that he could only see through one eye. In the evening he arrived where his house had been, but could not find it. He later learned that it had burned and collapsed, and that his mother had died inside, while his father and sister were safe.

Remembering that some of his father’s friends lived on the north outskirts of the city, he set off to walk there. Around midnight he collapsed in a field, but neighbours found him and took him to his destination. Seriously ill, he now entered another nightmare, the uncharted world of radiation sickness.

That night I lost consciousness. I had a very high fever. I was ill in bed for about a month. Every day pus flowed from my wounds. I cried every day and every night. The radiation had not affected me badly. But my aunt visited me while I was in bed. She looked healthy, not wounded or burnt. But about ten days after, she died with black foam coming from her mouth. She was near to the bomb when it exploded.

After a month, his wounds were almost healed, though like many survivors he had keloid scars — rubbery, itchy, and disfiguring red growths that formed over the bad burns they had suffered. Japanese doctors were unsure how to treat the keloids: if removed, they often recurred.

“I had surgery twice for the keloids: once next spring and once next summer,” Hiromu said. “They cut off the keloid and grafted skin from my thigh onto my face near my mouth. The next time they cut on my neck, but they didn’t cut away enough, so the skin was still a different color and itchy.” He was a teenager, and felt anxious that girls wouldn’t find him attractive because of how his face looked.

Hiromu stayed in the countryside for six months or so with friends of his grandmother’s — there were still food shortages in the towns. Next spring he returned to Hiroshima to continue school, and discovered that around half of his classmates had died in the bombing. There were tensions with the American occupiers: “the American Army came to Hiroshima and the country areas in jeeps — a lot of soldiers. Some friends, when the atomic bomb was dropped, they wanted to attack the American bombers.”

One point of contention was the Atomic Bomb Casualty Commission, established by the Americans in 1946 to research the effects of the bomb on survivors — but not to treat them. “We felt that they must treat survivors. We hated them.” The Americans also censored the Japanese press. “Generally you couldn’t write about the bomb, though some people tried to. The Americans wanted to make another atomic bomb, a hydrogen bomb. So they needed to keep the information secret about survivors and the atomic bomb’s destructive effects.”

Over time, Hiromu came to feel that research into the bomb’s effects could be useful, and that the most important thing was to prevent war in future. “I felt that so many people had been killed and so much destroyed and burnt, everything had come to an end. I believed that maybe all people in the world will not fight again.”

Yet only five years after the bombing, the US and Soviet Union began a proxy war in Korea. “When the Korean War happened, there were many tanks and bombs brought here to Japan for the war. Every day you saw them on the railroads. We felt very near to Korea. We were students, we organized protest meetings against it.”

Hiromu became a teacher of the traditional Japanese art of calligraphy, a trade unionist and an anti-war campaigner.

We thought — we were teachers, we must teach the next generation of young people the facts about the atomic bomb. I’ve been to many countries — as a survivor, part of the peace movement, or with other members of the trade unions. I’ve been invited to India and China with the teachers union to talk about my experiences. Now China, Pakistan, and India have nuclear weapons, and Iraq and North Korea want to have them. But the Americans have the most nuclear weapons: they should abandon them first. I will protest against nuclear weapons until I die.

You have only to raise the demand that America give up its atom bombs to see how far platitudes about democracy and justice are from the reality of American military power. That reality, in 1945, meant terrible injuries for a fourteen-year-old Japanese boy and many more like him. Our rulers, with America at their head, will continue to maintain themselves in power by torturing and killing children, unless and until we stop them.