As a young medical student in post-war Malaya, Dr Ronald McCoy read Hiroshima by John Hersey, a 1946 report published in The New Yorker detailing the aftermath of the atomic bomb through the eyes of six individuals.
The horrifying accounts deeply affected him but he felt helpless over how to prevent such utter devastation from occurring again.
"I didn't think there was anything I could do about it," Dr McCoy told The Straits Times.
But there was.
Decades later, Dr McCoy heard of and joined IPPNW, the International Physicians for the Prevention of Nuclear War. Years of campaigning to eradicate nuclear weapons led the retired obstetrician to found the International Campaign to Abolish Nuclear Weapons (Ican) 10 years ago.
On Oct 6, Ican won the Nobel Peace Prize, after the United Nations announced in July that 122 countries had signed on to adopt a total ban on nuclear weapons.
The first UN treaty of its kind, it is legally binding and comes into effect once 50 nations ratify it. Absent from the negotiations were the nine nuclear-armed states and their allies, while Netherlands voted against it and Singapore abstained.
"A lot of people in the world don't understand what are the consequences of a nuclear war," Dr McCoy said in an interview at his home in Petaling Jaya.
"There is the feeling that no matter what they do, nuclear weapons won't be disarmed. But if there is a human problem, surely there is a human solution."
The founding of Ican, Dr McCoy said, stemmed from the 2005 failure of the Non-Proliferation Treaty (NPT) to produce any agreed action plan.
"It felt like barking up the wrong tree… So I said, 'Let's take nuclear disarmament out of the NPT process, which was not working, and let's form an international campaign to abolish nuclear weapons'. That is how we got Ican."
A sprightly 87-year-old, Dr McCoy has had an illustrious career delivering more than 20,000 babies during his 40 years working as a doctor in Malaysia.
Watching over soon-to-be mothers and their babies, Dr McCoy could not shake off the feeling of responsibility for children growing up in a world with nuclear weapons.
"This baby now lives in a world bristling with nuclear weapons and the threat of a nuclear war… To me, I have an extended responsibility to do something about that," he said.
He added: "As doctors, we cannot do anything in a nuclear war… Nuclear disarmament is a kind of preventive medicine."
Dr McCoy said that the countries possessing nuclear weapons cannot use the excuse of deterrence to justify having such destructive arms.
"You can't forever rely on deterrence without an accident occurring one day," he said.
The road to eradication of nuclear weapons, Dr McCoy believes, has to come from the country with the most nuclear arms - the United States.
"If the US gives these up, other nuclear states would give up their nuclear weapons. The change has to come from the US."
Despite his age, Dr McCoy has not slowed down. Spending his days responding to e-mails and reading the news and reports on nuclear weapons disarmament, he stays healthy by doing light exercises at home.
Dr McCoy, whose father was a civil servant with Malayan Railways, grew up in Kuala Lumpur.
It was a five minute-walk from his home to his primary school in Pudu, an old neighbourhood in KL; later, he cycled daily to the prestigious all-boys Victoria Institution for his secondary school education.
Of Anglo-Indian descent, Dr McCoy said many people are surprised to learn that he is Malaysian. "Maybe it is my name and the colour of my skin. So I would say, 'I am 200 per cent Malaysian'," he said in jest.
Although he thinks that it will be "a tough road ahead" for nuclear abolition, the bright and cheerful grandfather of four is optimistic that nuclear weapons disarmament is possible.
More so after the UN treaty to prohibit nuclear weapons was passed.
"You should have heard the roar in the room when they announced it!" he exclaimed.
"When we get to zero nuclear, I won't be around. But do leave me a forwarded message and wherever I am, I will celebrate," he said, smiling.
The Nobel Peace Prize will be presented on Dec 10 in Oslo, Norway. Dr McCoy will be attending the ceremony.
When asked if he could impart any advice to the younger generation, he said: "Love your fellow human beings. What could be more needful than that today?"
Correction note: The headline has been edited for clarity. We are sorry for the earlier error.