The fevered race to build an atomic bomb during the second World War famously ended in an airburst 580m above Hiroshima that killed 140,000 people and incinerated the city in August 1945. The destruction of Nagasaki and another 70,000 lives followed three days later.
Less well known is that wartime Japanese scientists were also trying to build a bomb.
A new Japanese movie called Taiyo no Ko (Gift of Fire) for the first time dramatises that history, depicting the attempt to develop a nuclear weapon at Kyoto University, led by physicist Bunsaku Arakatsu, a brilliant protege of Albert Einstein.
There is a sense that this is hidden history and many are surprised to learn it
The Imperial Japanese Navy ordered an initially sceptical Arakatsu to build a bomb in 1942. A separate bomb project, commissioned by the army, was undertaken in Tokyo under Yoshio Nishina, known as the father of nuclear physics in Japan.
With its vastly greater resources, the US tested the first atomic bomb in New Mexico in July 1945 before unleashing the weapon on Japan, which surrendered a few days later. The US-led occupation cast Japan’s A-bomb programme into history, destroying the rudimentary laboratory equipment in Kyoto and Tokyo.
The director of Gift of Fire, which opened at 250 cinemas across Japan in August, told The Irish Times that few young people know this story. “There is a sense that this is hidden history and many are surprised to learn it,” said Hiroshi Kurosaki, who spent 10 years trying to finance his film.
The history isn’t actually secret, Kurosaki stresses. “All the information is freely available but it’s in academic studies, not in novels or movies. I researched from off-the-shelves books in a Hiroshima library. It’s just that almost nobody wanted to tell the story, and that aspect I found really interesting.”
Kurosaki hangs his tale on a group of idealistic young scientists under Arakatsu, who says their task is to “release the power of the atom”. The work is given urgency by the war raging outside their cloistered circle. Nearly everyone has family fighting abroad. Newsreel footage shows kamikaze pilots (many in their teens) crashing planes into enemy ships in a doomed attempt to stop the American invasion.
'After the war, I think that the fact that Japan was a victim of nuclear weapons but was trying to develop one itself became a taboo.' Photograph: US Defense Department/Reuters
The central character, Ryu Ishimura (played by Yagira Yuya), spends much of his time trying to source scarce uranium nitrate from a local potter who uses it to dye his urns. The scientists develop a series of cyclotrons, charged particle accelerators used to isolate isotopes present in the uranium – the first step toward nuclear fission.
Japan's school textbooks spend little time dwelling on the darker aspects of its war
During a US air raid, the scientists debate their research. “If we dropped the bomb on San Francisco an estimated 200,000 people would die,” says one. “300,000,” he is corrected. “If we don’t build it the Americans will; if they don’t the Soviets will,” says another. When someone questions the ethics of their work a young engineer angrily shouts: “My brother died. I don’t want his death to be in vain.”
Later we watch Ryu walking among makeshift funeral pyres burning great piles of bodies in Hiroshima’s blasted landscape. “This is the reality of what we are trying to achieve,” he muses darkly. Arakatsu seems to have his eyes set on the world after the fighting stops. Wars are fought for energy, he says. If scientists can create unlimited energy, it might take away the reason to fight.
Japan never came close to enriching enough uranium to make a weapon, only one of the technical problems it struggled to overcome. A German Nazi submarine attempting to deliver a large cache of uranium oxide to the Japanese military was captured in 1945.
Hiroshima after the war became what writer Ian Buruma calls the centre of “Japanese victimhood”, a pilgrimage with the “atmosphere of a religious centre”. Millions of schoolchildren have made that pilgrimage but school textbooks spend little time dwelling on the darker aspects of Japan’s war.
The movie could hardly be timelier. In January, the Bulletin of the Atomic Scientists put the hands of its famous doomsday clock close to 100 seconds before midnight, the closest it has been to symbolic doom in 70 years.
In April, Japanese government officials shocked anti-nuclear campaigners by opposing a proposed US policy of no-first-use of nuclear weapons.
“It would be tragic if Japan, the only country to suffer nuclear attacks, and a staunch advocate of the abolition of nuclear weapons, blocked this small but important step toward the abolition of nuclear weapons,” said a group of scientists and activists.
Kurosaki says it’s time to study history. “After the war, I think that the fact that Japan was a victim of nuclear weapons but was trying to develop one itself became a taboo. I think it is important to face that contradiction.”
Gift of Fire is due to be screened outside Japan in late 2021