80 years after Hiroshima and Nagasaki: Is the world on the brink of a new nuclear arms race?

Fears of nuclear proliferation are growing in the world amid heightened geopolitical tensions, increased militarisation, and massive defence budgets.  The fear reached new heights on June 13, when Israel launched a bombing campaign against Iran, in what it said was an aim to prevent the Islamic Republic from developing a nuclear weapon -- an ambition Tehran has consistently denied. 

As Japan prepares to mark the 80th anniversary of Hiroshima and Nagasaki on August 6 and August 9, 2025, respectively, is the world heading towards a new nuclear arms race?

On August 6 1945, the United States dropped an atomic bomb on Japan's Hiroshima. Three days later, it dropped the second and last ever detonated nuclear bomb used in warfare on Nagasaki. More than 200,000 people died as a direct result of the bombings, 38,000 of them children.

Jorgen Watne Frydnes, president of the Norwegian Nobel Committee, says a powerful international norm was developed after the bombings, stigmatising the use of nuclear weapons as morally unacceptable. "This norm has become known as the 'nuclear taboo'. It is therefore alarming that today this taboo against the use of nuclear weapons is under pressure," he told AFP. 

Despite the devastation caused by the bombs, countries continued to develop nuclear warheads in what became an atomic arms race between the US, the former Soviet Union and their respective allies. Amid heightened geopolitical tensions, there are now growing concerns around a renewed nuclear arms race.

Russian President Vladimir Putin has wielded the nuclear threat on several occasions since Russia's 2022 invasion of Ukraine, aiming to deter the West from militarily aiding Kyiv.

Russia possesses 5,459 nuclear warheads, the most significant number in the world, just ahead of the United States, which has 5,177, according to Stockholm International Peace Research Institute (SIPRI) data from January 2025. The two countries hold nearly 90% of the world's nuclear arsenal.