Ultimately the decision to drop the bombs was made by US President Harry S. Truman, hoping to bring about a quick resolution of the war by inflicting mass destruction on Japan. This act was the culmination of over 3½ years of direct involvement of the United States in World War II, during which time it had suffered about a million casualties. When the Japanese mounted a surprise attack on Pearl Harbour on 7 December 1941 the US was drawn into a war against an apparently brutal and fearless enemy - one who chose death and honour over surrender and defeat. It has been argued that the attack on Pearl Harbour provoked a genocidal rage among many Americans; public opinion polls in the United States at the time consistently showed 10 to 13 per cent of all Americans supported the 'annihilation' or 'extermination' of the Japanese as a people. This was a war without mercy, and the US acknowledged as much in 1945, to devastating effect.
At the time of its bombing, Hiroshima was a city of considerable military significance. It contained the headquarters of Field Marshal Hata's 2nd General Army, which commanded the defence of all of southern Japan. The city was a communications centre, a storage point and an assembly area for troops. It was chosen as a target because it had not suffered damage from previous bombing raids, allowing an ideal environment to measure the damage caused by the atomic bomb. The city was mobilized for "all-out" war, with thousands of conscripted women, children and Koreans working in military offices, military factories and building demolition and with civilians training to resist any invading force. Truman saw this as sufficient reasoning for ordering its destruction.
It was a brilliantly clear morning in Hiroshima when the American B-29 Superfortress bomber Enola Gay dropped the bomb, nicknamed 'Little Boy' by its makers. It was three metres long and weighed four tonnes and seconds later it became the most destructive weapon the world had ever seen. At 8.15am the uranium atom bomb exploded 580 metres above the city with a blinding flash, creating a fireball that blazed with a temperature of more than a million degrees Celcius at the centre. In one second the fireball reached a diameter of 280 metres, sending surface temperatures to 4,000C. Fierce heat rays and radiation burst out in every direction, unleashing a high pressure shockwave, vaporising tens of thousands of people and animals, melting buildings and streetcars, reducing a 400-year-old city to dust.
Aside from the immediate death toll, the trauma left by the bombing echoed through the decades, in particular the legacy of the powerful radiation and gamma rays triggered by the A-bomb, which poisoned the large ashen drops of 'black rain' drunk by thousands of thirsty survivors. Dozens of babies who had been in their mothers' wombs when the bomb exploded were born with microcephaly - abnormally small heads. From around 1950, cases of leukaemia in Hiroshima soared, and from around 1955 thyroid, breast, lung and other cancers increased. Fears persist that the problem will pass down generations. From early 1946, many people exposed to direct heat rays up to two kilometres from the hypocentre of the blast suffered burn scars that were thought to have healed. However these lesions began to swell, the skin contorting into obscene growths that caused major disfigurement that was not tolerated by Japanese society; marriages fell apart, victims were discriminated against in the workplace, driving many to suicide. The A bomb survivors - or hibakusha - became pariahs in their own land.
After the war, the unenviable task of rebuilding Hiroshima was underway, with new modern buildings rising all over the city. Also, as a result of the atomic bombing, Hiroshima began to receive donations of trams from all over Japan so as to reconstruct its public transport system. Today Hiroshima is the only city in Japan with an extensive tram network. In 1949, Hiroshima was proclaimed a City of Peace by the Japanese parliament, at the initiative of its mayor Shinzo Hamai. As a result, the city of Hiroshima was receiving more international attention as a desirable location for holding international conferences on peace as well as social issues. In 1985 Tens of thousands of people marked the 40th anniversary of the atomic bombing of the city on August 6, a sombre and poignant occasion that will no doubt be repeated this year.
THE LIVING REMINDER
Today Hiroshima is a thriving city with a population of 1.1 million and full of all the trappings that define the hustle and bustle of modern society. However the A-bomb that killed tens of thousands of people here, defines it - and probably always will. At the city's heart is the memorial peace park and museum, where school pupils look at exhibits left behind, including school uniforms ragged and scorched, a lunchbox of carbonised food, a pocket watch stopped at 8.15am and in particular, a glass case containing the cut-away steps of the local Sumitomo bank; whoever was sitting on those steps became reduced to a mere smudge. This park exists that we never forget, but perhaps a more sobering reminder is that in 2005, sixty years on, there are over 80,000 hibakusha still alive and living in the city. This is not some fading footnote from the pages of history and it is paramount that we never forget the horrors that took place here.