I am of the lucky baby boomer cohort born after World War II and before the mid-1960s. It is a generation that has never experienced a world war and grew up during the longest sustained period of prosperity the world has ever known.

Except for brief periods of regional conflict such as the Korean and Vietnam wars, and the financial turmoil in 1997 and 2008, baby boomers of the Asia-Pacific have for the most part led a charmed life of peace, abundance and hope, or at least I thought.

I often wondered what it was like with previous generations who were not so lucky. My parents were barely in their teens when the Pacific War started - my mother in her home village in Hainan, China, my father in Singapore.

The pain and suffering they endured at such a young age must have had a profound impact on their lives, their careers and the way they raised their families, moulding their character and values along the way.

It is the case for every generation. My father passed away two months ago at the age of 91 after a short illness with bile duct cancer.

His education had been interrupted by the Japanese invasion of Singapore in 1942.

During the three-year Occupation, he worked as an errand boy for a Japanese officer in charge of procuring fish from Batam. He would spend three to four days a week with the officer on the Indonesian island and return to Singapore with the week's supply for Japanese soldiers based here.

For a 13-year-old boy, it was life and death.

Life meant learning fast how to survive and get out of tricky situations and making do with what little you had.

Death was always close by. He lost his elder brother who had joined one of the anti-Japanese resistance forces, and was captured and tortured. When he was eventually released, he was so weakened he succumbed to malaria shortly.

His mother - my grandmother - was so grief-stricken, she never forgave Japan and held a lifelong hatred for its people. My father must have felt her pain but did not share her animosity towards Japan.

Every generation is different. Even when the experience is the same, age is a great differentiator.

I am recalling this now because my father's death signalled the end of an era. He was, for me, the last survivor of his generation.

In a selfish way, I was glad he passed away just as the Covid-19 pandemic was under way.

His illness was terminal and it was a matter of time. He had led a full life and it was better that he did not have to suffer the consequences of the disease and the devastating fallout that is sure to follow.

He and his generation had been through one life-destroying horror and did not deserve to go through another.

This pandemic is the baby boomers' to face and deal with. Unlike my parents' generation, it has come at the tail end of ours.

Hence, it will not shape us the way our parents were by the war. They were children when they had to face their crisis and could do nothing about it but try to survive.

But we are now grown up, some at the peak of their careers, others in retirement. Whatever our circumstances, this global horror is our generation's defining moment.

Our parents had the world war and the wars of independence to define theirs.

What about the baby boomers' defining moment? I can't think of one event that is global and which every baby boomer in every corner of the world can say, this was it.

Some might say: What about how baby boomers have made the world a better place with growth and prosperity the last 70 years, lifting millions from poverty?

It is an achievement not to be sniffed at. But it is not a defining moment. It is also a tainted one with large numbers of people still living in poverty amid an ever-widening income and wealth gap in many countries.

The unrelenting march to progress and industrialise is also causing an ecological disaster with global warming. The impending climate change might have been a challenge for baby boomers to rise to and overcome. That is a defining moment, if ever there was one, to seize and change the future.

Alas, our generation looked the other way and the effort has been fitful and half-hearted.

It is such an indictment that when climate change issues are discussed today, it is the younger generation - particularly millennials - that is often said to be more interested and committed to doing something.

Baby boomers are instead seen as the problem, too set in their ways and unwilling to give up their often wasteful lifestyle. Or too selfish because the consequences will not be theirs to suffer but their children's and grandchildren's.

Perhaps when historians look back at this, they will record it as a defining moment - of lost opportunity.

So, we are left with this pandemic, and all the more urgent for baby boomers because they are the most vulnerable group with a greater chance of dying from it.

If not this moment to seize and do something, then when?

In fact, baby boomers are in charge in almost every aspect of the challenge, in politics with the likes of Mr Donald Trump, Mr Xi Jinping and Dr Angela Merkel leading their countries' fight, in healthcare with Dr Tedros Adhanom Ghebreyesus of the World Health Organisation (WHO), and with prominent advocates of global action such as Mr Bill Gates.

What will count as a defining victory for the generation?

Top priority is developing a vaccine. But it has to go beyond just one vaccine because there will be other viruses in the future.

There has to be an international effort to coordinate a global network of medical and research facilities to speed up future vaccine development quickly and safely.

This will require substantial investment and international cooperation among all nations.

It has to be much more effective and resourceful than the WHO and more proactive in tracking potential viruses before they make the jump to the human population.

If baby boomers can help develop such an infrastructure to keep future generations safe from pandemics, it will be their signal contribution. But it will still not count as a defining moment for the generation.

For it to be so, it has to touch every person's life in a meaningful way, perhaps changing it forever.

It has to be a moment when you can look back and tell your grandchildren stories of what you did and how it changed you.

What can you tell them when all this is over and they ask: What were you doing during the Great Pandemic of 2020? What stories can you tell them to match those your parents told you about the war?

I hope the answer will not just be: I stayed at home. Or I really missed my bubble tea.

Even though it is of the utmost importance during this stage of the crisis to stay at home, I think if we want this to be the defining moment of our generation, it has to go beyond just this.

Every baby boomer should ask what this pandemic means to him or her, individually and collectively, and what he or she should do about it.

Help the poor and vulnerable who are hardest hit? Foreign workers who now have the most number of infected cases? Front-line healthcare workers and others directly involved who put themselves at risk every day?

It can be as simple as helping to spread the message to stay safe and healthy.

In fact, many are already doing so, providing free food for migrant workers, sheltering the homeless and donating to charities.

But it also need not be any of these, or anything heroic. This is about your own personal journey that you make with your fellow baby boomers, every one with a unique story to tell.

You need to have both a collective sense of the crisis that is connecting you to everyone else in the world and your own personal sense of what it means to you and how it will affect and change your life.

Baby boomers can do this meaningfully because they are at a reflective stage in their life but still with the energy to do something about it.

Even if you are not sure what to do now because of the stay-at-home rule, there will be plenty to do later following the severe economic fallout that will devastate businesses and livelihoods, and which may last for years.

In making this call to baby boomers, I am not downplaying the role of the younger generation.

They too can and should do as much as they can, but they have a lifetime to act and find their own defining moment.

Baby boomers do not have this luxury and so have to act urgently, if not for themselves, then for the younger generation.

Like for my first grandson who was born five months before my father died.

What stories can I tell him?

• Han Fook Kwang is also a senior fellow at the S. Rajaratnam School of International Studies, Nanyang Technological University.