Eighty years on from Hiroshima

At 8:15 a.m. on August 6, 1945, a nuclear bomb exploded just above Hiroshima, instantly killing at least 70,000 people. Another 70,000 died of injuries and radiation sickness before the year ended. Three days later, a second weapon exploded over Nagasaki, killing 40,000 on the day. In the 80 years since, nuclear weapons have not been detonated again in anger even though the possessor states have swelled from one to nine, and the number and sophistication of the weapons has increased considerably. A norm of non-use appears to have been established. However, norms — shared expectations of behaviour — are not immutable. Recent developments including hostilities involving nuclear possessors, an undermining of the global rules-based and treaties-based order, and nuclear modernisation are putting the norm of non-use under immense strain.

Lessons from 1945

Arguably, no one has worked more passionately to eliminate nuclear weapons entirely than the Hibakusha, the survivors of the atomic attacks. Their testimony created a powerful moral and ethical case against nuclear use, reminding us of the human consequences of — arguably for some —  a demonstration of American resolve and technological prowess. Yet the respect that they are accorded today was hard won. Japan was under American occupation after the war, and information on the effects of the nuclear bombings was suppressed. According to one survivor from Nagasaki, shortly after the bombing, U.S. Brig Gen Thomas Farrell announced that all those affected by the attack had died and that there were no continuing effects of the bomb. Relief centres were shut down. An additional 50,000 people died by December without understanding what ailed them.

Knowledge about radiation sickness became widespread in Japan only after a fishing boat, Fukuryu Maru, was accidentally exposed to nuclear fallout. The U.S.’s 1954 thermonuclear test, codenamed Castle Bravo, ended up twice as powerful as estimated, spreading radioactive ash well beyond the officially designated warning zone and to the vessel floating 86 miles away from the test site. All crew members fell seriously ill from acute radiation poisoning. Thus it was that nine years after the bombing of Hiroshima and Nagasaki that Japan began to understand the nature of radiation sickness: the bomb killed not just by explosion, instantly, but painfully, over time. The survivors then grouped together as the Nihon Hidankyo and fanned the globe to educate people on the horrors of their experience.

It is debatable whether the norm of non-use owes more to the moral and ethical case against nuclear use made by the Hibakusha or by the logic of nuclear deterrence. ‘What deters’ is a question that has occupied policymakers for decades. And while the total number of nuclear weapons has fallen from their Cold War peak, today’s nukes are more sophisticated and designed for use in a range of situations. Much money and effort has been spent in developing more ‘useable’ nukes. It is difficult to know whether to worry more about a thermonuclear weapon that could destroy a city several times over, or to fear tactical weapons that are designed to target a specific location with deadly accuracy. For 80 years we have decided that nuclear weapons are beyond the pale: any nuclear use now would let the genie out of the bottle.

The norm of non-use

Ultimately, the norm of non-use rests on a conscious decision to brand nuclear weapons as different. There is no legal basis for the circumscribing of their use. The Nuclear Non-Proliferation Treaty (NPT) limits the spread of nukes; the Comprehensive Nuclear Test Ban Treaty bans nuclear tests; neither prohibits use. (The 2017 Treaty on the Prohibition of Nuclear Weapons has not been signed by any nuclear possessor.) However, the NPT’s exhortation to nuclear states to work towards total nuclear disarmament “in good faith” puts the weapons in a separate category. The International Court of Justice’s 1996 advisory opinion on nuclear weapons constrains their use by stating that the use or threat of use “would generally be contrary” to humanitarian and other international law, even though the Court was unable to reach a clear decision on their legality. Together, these treaties shore up the norm of non-use, without legally proscribing them.

Against this backdrop, recent nuclear threats bandied about by Russia over Ukraine have severely tested the special categorisation of nukes. Closer home, during Operation Sindoor, Prime Minister Narendra Modi declared that India “will not tolerate any nuclear blackmail”. A “limited” operation appears to have escalated quickly to acquire a nuclear element.

We are influenced by the Hibakusha’s testimony today only because Fukuryu Maru’s misfortune connected radiation sickness to nukes. It is also unlikely to be a coincidence that the Nihon Hidankyo were awarded the Nobel Peace Prize in 2024 for their disarmament efforts after the nuclear genie reared its head in Europe. They had been nominated multiple times, but it took almost 70 years for the survivors’ efforts to be recognised.

Eighty years after nuclear weapons were used in anger, we are in danger of slipping into complacency over nuclear use. It took the miscalculation of America’s thermonuclear test for the truth about nuclear fallout to become widely understood. We should not wait for another misstep before the dangers of nuclear miscalculation are appreciated again.

Priyanjali Malik writes on politics and international relations