Some readers who are not Singaporeans might understandably be puzzled by references to "3G" or "4G", which means third generation and fourth generation respectively. Therefore, before I discuss the transition to the 4G leadership, it may be useful to quickly recap the different generations of leadership.

A different "G" label - indicating a distinct generational change - for different prime ministers' Cabinets is somewhat of a misnomer, and perhaps even misleading.

This is because each prime minister had a mix of ministers who were new and young, as well as older and more experienced. Several ministers served in the Cabinets of more than one prime minister.

For example, I was one of the few ministers who had the unique privilege of having served all three prime ministers. I was first elected as a Member of Parliament in 1980, appointed as a minister of state in 1981, and became a full minister in 1984, and I stepped down in 2011.

Prime Minister Lee Kuan Yew's Generation of Leaders (1G)

Looking back, PM Lee Kuan Yew's team was the 1G leadership, although hardly anyone uses that term to refer to the founding fathers' group. PM Lee Kuan Yew's key Cabinet colleagues included Goh Keng Swee, S. Rajaratnam, Toh Chin Chye, Eddie Barker, Ong Pang Boon and Othman Wok.

PM Lee Kuan Yew served as PM for 31 years. In the latter half of the 1970s, he brought into his team younger people whom he hoped to test out to form the next generation of leaders. They included Goh Chok Tong, Tony Tan, Ong Teng Cheong,

S. Dhanabalan, Lim Chee Onn and myself.

Prime Minister Goh Chok Tong's Generation of Leaders (2G)

Goh Chok Tong became Prime Minister in 1990 and stepped down in 2004, serving as PM for close to 14 years.

The process by which the 2G leaders selected him has been recounted, first by myself and later, by Goh Chok Tong himself.

In December 1984, Tony Tan organised a coffee/orange juice session at his home, attended by Ong Teng Cheong, S. Dhanabalan, Yeo Ning Hong, Ahmad Mattar, Lee Hsien Loong and myself. Chok Tong himself joined the meeting later. Several ministers of state were also present.

It was not a lengthy meeting and we decided that the leader of the team should be Goh Chok Tong.

PM Goh Chok Tong's team of key ministers included those present at that meeting, as well as Wong Kan Seng, Lim Hng Kiang and Lim Boon Heng.

Prime Minister Lee Hsien Loong's Generation of Leaders (3G)

Lee Hsien Loong, who entered politics in 1984, became Prime Minister in 2004, and at the time of writing, he has served 16 years as Prime Minister.

Before that, he was Deputy Prime Minister for almost 14 years in Goh Chok Tong's Cabinet.

PM Lee Hsien Loong's 3G team of key ministers included Teo Chee Hean, Tharman Shanmugaratnam, Ng Eng Hen, K. Shanmugam, Lim Hng Kiang, Wong Kan Seng, Vivian Balakrishnan, Khaw Boon Wan, George Yeo, Yaacob Ibrahim, Mah Bow Tan and myself.

The process of selecting Lee Hsien Loong as PM was simpler. He had been appointed as DPM in 1990 and his performance as DPM had been outstanding. None of us in PM Goh Chok Tong's Cabinet had any doubts that he should succeed Goh Chok Tong as Prime Minister.

Sometime in mid-2004, Wong Kan Seng organised a lunch among ministers at his office and as Lim Boon Heng recalled it, the meeting was short because "the choice [of Lee Hsien Loong] was clear".

How did the 4G decide on new leaders?

The process of selecting the 4G leaders was also different.

In December 2017, Goh Chok Tong, who was then Emeritus Senior Minister, nudged the 4G team to settle the question of leadership early so that PM Lee Hsien Loong could settle on his successor by the end of 2018.

However, the 4G team did not want to be rushed into a decision and on Jan 4, 2018, 16 ministers from the 4G issued a joint statement that they were "conscious of their responsibility, are working closely together as a team and will settle on a leader from among us in good time".

On Nov 23, 2018, almost 11 months later, 32 ministers and Members of Parliament issued a joint statement: "Now we have a consensus that the team will be led by Swee Keat."

They also noted that Heng Swee Keat had asked Chan Chun Sing to be his deputy, and Chun Sing had agreed to this.

In their joint statement, they said: "We endorse and support Swee Keat and Chun Sing as our leaders."

This ended months of speculation at that time on who the next PM might be.

On April 23, 2019, PM Lee appointed Heng Swee Keat as his DPM with effect from May 1, 2019.

This reinforced the expectation that he would become Singapore's next prime minister sometime after General Election 2020 (GE2020). It seemed that the only question was when PM Lee would step down.

Before 2020, PM Lee Hsien Loong had hoped to step down by his 70th birthday

In mid-2017, PM Lee Hsien Loong set out his thoughts on how long he planned to remain as Prime Minister.

He said that the next general election (which was held on July 10, 2020) would be the last that he would lead as Prime Minister, and added that he hoped to step down before he turned 70 years of age (which would be in February 2022).

Going by this, Singaporeans expected to have a 4G prime minister sometime in 2021 or 2022.

Many Singaporeans expected and hoped that after stepping down as PM, Lee Hsien Loong would continue to be in the Cabinet, just as former prime ministers Lee Kuan Yew and Goh Chok Tong did after they stepped down as PM.

I asked PM Lee Hsien Loong if he had announced his intentions prematurely

After PM Lee announced his intention to step down after the following general election (held in July 2020), many people were concerned and disappointed. They included not only my friends but also some taxi drivers with whom I sometimes had interesting conversations during taxi rides.

They wondered why he made that announcement when the identity of his successor was not yet known, and even if it was known, such a person would have to be tested.

They asked: "Why could PM Lee not have waited?" After all, he was young and fit enough for at least two, if not three more terms. They hoped PM Lee would change his mind and urged me to persuade him to do so if I should meet him.

These concerned people agreed that the key members of the 4G - Heng Swee Keat, Chan Chun Sing, Tan Chuan-Jin, Ong Ye Kung and Lawrence Wong - all appeared to be capable and competent, but still, they expressed some reservations.

Some were concerned about Heng Swee Keat's health, as he had suffered a stroke in May 2016 because of an aneurysm. He was tipped to be the leader of the 4G. Fortunately, Heng Swee Keat made a complete recovery after immediate surgery.

Other typical comments they made were: "they are not ready" or "they do not have enough experience in politics".

I reminded them that I myself had been pulled out from the university with zero experience in politics and after one year of being a Member of Parliament, I was appointed to political office, first as minister of state, then as full minister. The only non-academic experience I had was serving as Singapore's Permanent Representative to the United Nations from 1971 to 1974.

There were several others in the 2G team who also became ministers without any prior political experience.

PM Lee Hsien Loong used to invite me to lunch periodically, mainly to discuss our preparations for Malaysia's application to revise the International Court of Justice's 2008 Judgment on the Pedra Branca case. (I was chairman of the Inter-Ministry Committee preparing for that case.)

During one such lunch in the later part of 2017, I told him about the feedback I had received.

He said he was aware and, in fact, had also received such feedback. However, he had clearly given the matter careful thought.

He explained that if he postponed the timeline, it would not be good for Singapore. He would be much older, and so too would be his successor.

It would be better if the new PM and his key team members were to take over earlier. I found his explanation persuasive.

He was determined in not wanting to stay on as the nation's leader longer than necessary.

All this was, of course, before Covid-19.

Revisiting PM Lee Hsien Loong's timeline on succession during the Covid-19 pandemic and post-GE2020

After the onset of the Covid-19 pandemic and after GE2020, the views that PM Lee should remain longer at the helm have intensified.

When PM Lee had earlier expressed his thoughts about when he would step down, nobody had expected the tumultuous calamity that Covid-19 would inflict upon Singapore and the world.

It is Singapore's worst crisis. It has had grave consequences for the health and lives of the people as well as Singapore's economy.

All signs point to a long-drawn-out crisis. PM Lee has clearly realised that we are in an extraordinary situation.

At his online Fullerton Rally Speech on July 6, 2020 during the election campaign, he said he had not expected to encounter such "an overwhelming crisis" in the last stretch of his premiership, and added: "You have my word: Together with my older colleagues like Teo Chee Hean and Tharman Shanmugaratnam, as well as the 4G ministers, I will see this through. I am determined to hand over Singapore intact and in good working order to the next team."

He repeated this assurance almost verbatim in his televised comments on the GE2020 results in the early hours of July 11, 2020.

He put it another way at the press conference on July 25, 2020 on the new Cabinet line-up: "I do not determine the path of the Covid-19 pandemic, and a lot will depend on how events unfold."

I am glad that PM Lee has given himself some flexibility on the succession timeline. In my view, however capable the 4G leaders, we should not change horses in midstream.

Another question further down the road is this: what if the crisis takes even longer to abate? What if Singapore is still in dire straits in four to five years' time closer to the next general election?

Would PM Lee also be prepared to revisit his earlier intention not to lead the next general election as PM?

Of course, if "normalcy" has been restored before the next GE, I think the public will support his desire to step down as PM. However, if the crisis persists, I believe many Singaporeans will want him to reconsider that aspect of his timeline as well, and hand over only after Singapore has turned the dangerous corner.

It is, of course, still early days, but that scenario has to be considered.

Much will depend on the success of measures taken to address both the health and economic fronts.

Quite apart from the pandemic, the coming four or five years will see a volatile external environment, especially with tensions rising between the United States and China. Singapore will need a pair of safe, experienced hands during this period.

Whether one or both aspects of PM Lee's timeline are adjusted, there will likely be some slippage in his schedule for handing over the reins to the 4G team.

The 4G leaders have shown a steady hand under very difficult circumstances. I and many other Singaporeans were encouraged by the calm and unruffled manner in which they tackled the many twists and turns of the Covid-19 crisis. In their regular TV briefings, they were transparent in setting out the facts, and confident in making and explaining decisions as the outbreak progressed.

However, PM Lee's indication that he will see the crisis through, in my view, gives a valuable opportunity to the younger 4G ministers (and even some of those newly elected MPs who were also made office-holders) to learn from PM Lee and the more senior ministers.

It is just like how I and my generation of ministers consider ourselves most fortunate to have learnt from the likes of Lee Kuan Yew, S. Rajaratnam and Goh Keng Swee.

Viewing political succession in context

I have alluded to the possibility that PM Lee's earlier planned schedule for handing over the reins to his successor may have to be adjusted.

Whenever any succession looms on the horizon, it is inevitable that there will be speculation, concerns and even anxiety. It is therefore important to view the issue of political succession in context.

With that in mind, let me make the following general observations.

Firstly, Singapore is fortunate in that all three prime ministers carefully planned for succession. Such succession planning has brought about many years of stability and continuity for Singapore.

In this regard, I recall that at the swearing-in ceremony of his eighth Cabinet in 1988, Prime Minister Lee Kuan Yew said that one of the important qualities by which political leaders are judged is "by the way they have provided for continuity so that a successor Government will continue to protect and advance the interests of their people".

Secondly, leadership succession is never any easy task in any country. Some countries do not consciously plan for it. Even when they do, things do not always go according to plan.

The next leader may emerge unexpectedly from nowhere with little or no experience in government. Sometimes, even a well-known figure, like Winston Churchill who enjoyed enormous personal prestige after leading Britain to victory in World War II, can be booted out from office.

Thirdly, even in countries like Singapore where leaders systematically plan for and groom successor teams, there can be bumps and hiccups along the way.

For example, it is well known that there were strong disagreements in the transition to 2G. Some of the old guard did not agree with the pace set by PM Lee.

More complications arose when PM Lee Kuan Yew publicly said that Goh Chok Tong had not been his first choice as his successor. Furthermore, to prod Chok Tong into improving his public speaking skills, PM Lee Kuan Yew described him as "wooden".

To his credit, Goh Chok Tong took all this in his stride. He proved to be a good prime minister, and he and the 2G ensured that the transition worked smoothly.

Fourthly, whether PM Lee Hsien Loong retires two years from now or a few years later, the exact timing is not the critical issue. What is important for Singapore is that there is no abandonment of the strategic impulse to plan for and execute an orderly succession.

The timing of handing over to the new team is a tactical decision, which will depend on many factors that every prime minister will have to weigh carefully, but hanging on to power cannot be a consideration.

Fifthly, for effective succession planning, we need to have a sizeable core of young capable leaders who have the potential to take over the reins. A prerequisite is that committed and competent people who care deeply about Singapore's future must be prepared to come forward and take on responsibility.

Of course, today, with social media's relentless and sometimes unfair scrutiny of the minutiae of a political candidate's personality, credentials as well as his past, it will be more difficult to persuade such good people to serve. However, if good people shy away, then even the best of succession planning will produce poor results.

I must confess that I too was nearly guilty of not agreeing to serve. In 1974 when the chairman of the People's Action Party, Dr Toh Chin Chye, first broached the idea of my entering politics, I demurred and said that I was not ready. He did not press me.

Later, in 1979, when Goh Chok Tong, through S. Dhanabalan, asked me to stand in the next general election, my first response was that I preferred to continue teaching law at the university.

But they asked me this question: "Supposing you are on the top of our list, and if you say no, and we have to go down the list and everybody else keeps saying no. We then go to the bottom of the

list and then later, would you regret it if things went awry in Singapore?"

When it was put in that way, I found it very difficult to refuse.

I urge every Singaporean who may be approached to serve, and who find themselves reluctant, to carefully ponder over the same question that was put to me decades ago.