The strategic vulnerability of Singapore will always dictate the need for a strong military deterrence. Therefore, I've assumed there is no need to even discuss this point: after all, an IPS survey has shown that an overwhelming 98 per cent of Singaporeans support national service.

Unfortunately, the survey also revealed that the main reason for supporting NS is that it is "good for our boys". The actual military rationale is not apparently the key consideration.

This would be a serious case of misplaced enthusiasm. Despite its success as a nation-building tool, deterrence must always be the primary reason for national service. The prolonged peace and stability we enjoy today, which many take for granted and as evidence that a strong deterrence is no longer necessary, is precisely and ironically because of that very same deterrence.

The difficulty of course, for the Government to convince Singaporeans about potential threats is that speaking about them only creates unnecessary tension with our neighbours and gives fodder for potential enemies to criticise us for scare-mongering.

I am under the same self-imposed censorship here: public settings are not appropriate venues to discuss the nature of our security threats nor raise convincing examples of the reality of that threat.

Therefore, I am reduced at this forum to simply remind ourselves that the politics of pragmatism or realpolitik, rather than wishful thinking, must always underpin Singapore's foreign policy; and so we must realise that geography is destiny. We are destined to be, with our immediate neighbours, sometimes the best of friends, and sometimes much less so.

What Theodore Roosevelt said about speaking softly but carrying a big stick, and what Lee Kuan Yew said about Singapore being only a small shrimp in the large ocean, but a poisonous one - these should probably be the pithy quotes inscribed on Safti's walls for all young SAF officers to read. A strong SAF is a strategic imperative, given our geo-political history and position.

And therefore we need to find ways to maintain, against the spectre of an ageing and declining population, the deterrent capability of not just our regular, but particularly our reserve forces. Even with outsourcing of some NS jobs and restructuring of organisational structures, a critical mass of reserve soldiers remains important even in the age of advanced technology and weaponry.

This starting point brings me to the elephant in the room when we talk about defence. But this time it is a she-elephant.

The question here is simple: will the time ever come when universal female conscription becomes necessary? And even if it does not become an absolute necessity, should we prepare for the possible eventuality, given the very long time-frame required for debate and preparation before any implementation?

After all, much debate and preparation will clearly be necessary. There is a huge caveat or qualifier to the overwhelming 98 per cent support of NS by our citizens. The same IPS survey revealed that only 9 per cent of all Singaporean women surveyed - and 13 per cent of those under 30 -- supported female conscription. A different study found broadly the same results: a higher proportion - 22 per cent -- of Singaporean women support female conscription, but only 9 per cent said they were willing to do it for two years. In other words, it's great for my father, husband, boyfriend, or son to do NS, but not me.

If we are to change young Singaporean women's views about female conscription - which by the way is gender-neutral in the Conscription Act -- the first challenge is to convince them there is indeed a demographic dilemma. Going by past attempts to raise the issue and the lukewarm response, much convincing remains to be done.

Current demographic trends from the United Nations show that in a "no-change" scenario - meaning we assume current Total Fertility Rates (TFR) and no in-migration - the male population aged 15 to 24 will decline by around 35 per cent between 2015 and 2040. A drop of one-third in 25 years. The rate of decline will continue so that in 50 years' time - by 2065 - the same male NS-age cohort then will be less than half of its size today.

While acknowledging this trend, Mindef has also said that with technological advances and organisational restructuring, the SAF can retain its same deterrent ability. Of course, I have no reasons to doubt Mindef. However, the flip side of this point is that, by the same token, these same technologies requiring more brain than brawn, are inherently female-friendly and will increasingly enable women to serve meaningful roles in the military.

As the nature of warfare changes, the classic image of thousands of foot-soldiers charging up a hill will necessarily evolve, possibly to one with armed drones skilfully and remotely controlled - by women.

Today, women make up 33 per cent of the Israeli Defense Forces, 15 per cent of the US military, and 7 per cent of the SAF regular forces. More than 90 per cent of the positions in the IDF are available for female soldiers. Starting next year, 100 per cent of vocations in the US military will be eligible for women.

While it is premature today to conclude that military conscription for two years for women will definitely become necessary, I would argue that we need to start changing mindsets soon. Otherwise it will be too late should the need actually arise one day, because of the inherent negative attitudes.

One way is to introduce universal female conscription for a form of non-military, shorter-term duration focussed on supporting our civil defence, Home Team, and even community and health-care institutions. This is not dissimilar to efforts already in place such as our Volunteer Youth Corps scheme, which should however augment and not replace the need to conscript females to meet our demographic challenge. After all, to bolster these capabilities is part of the notion of Total Defence which encompasses more than just the military.

Universal female conscription serves two purposes. One, it is socially unhealthy for our female citizens to support national service for men but to believe that serving the nation, even in non-military ways, is not required of them. A national service ethos and pride should be inculcated in our young women in the next 50 years of nation-building.

Two, should it ever become necessary to conscript women into military service, the challenge will be logistical and technical, and at least not attitudinal.

Universal female conscription could start with the Ministry of Culture, Community and Youth (MCCY), Ministry of Education (MOE) and our Civil Defence Forces (CDF) taking the lead, and with Mindef only providing whatever necessary technical support, so that this massive undertaking does not divert our military from its main role.

It could last several months and be held during the interlude between graduating from secondary school and entering tertiary institutions or entering the work force. Decentralised to the schools level for logistical purposes but with expertise provided by the uniformed services - the Home Team as well as SAF - the programme organised by MCCY could comprise a mix of school-level day classes, field practices, and Outward Bound style residential training. An annual equivalent of reservist training lasting several weeks during school term breaks could enhance the re-learning and refinement of para-medical, para-civil defence, or para-police capabilities.

The intention is to train future generations of female citizens who are not just actively engaged in the ongoing Total Defence of the nation but also equipped with real life skills which are different from, but no less important than, their male counterparts. Singapore in the next 50 years will certainly need a far more comprehensive voluntary services sector; national service-women could clearly contribute to their country in this area.

An important point however, is that to maintain the fundamental ethos of universal national service, it should be truly universal for all Singaporean young women and not be on a volunteer basis.

An interesting but slightly different parallel can be found in the Nordic countries, which are small and affluent like Singapore, currently enjoying peace but never complacent about external threats. Their approach is to embed universal conscription into law and have it become a socially acceptable norm, but without necessarily rolling it out full-scale unless the need arises.

In Norway, for example, national service for one year for women has just become law. However, their system of conscription is universal liability for the sake of equality but actual call up is far less than the liable pool. Less than 10 per cent of liable men and women are actually called up, and recruitment is based on self-motivation plus physical and mental fitness. But to maintain psychological readiness, universal conscription is considered a duty and is embedded into law. Denmark has a similar system, and Sweden will soon introduce the same.

Let me now move from external to the three dimensions of domestic security which I define as internal security, civil security, and societal security, to reflect their very different orientations.

Internal Security

I define internal security threats as clandestine and potentially violent activities which seek to subvert and undermine the ideological foundations of the state. These would be threats which mainly but not necessarily, culminate in terrorist activities. There are different origins of such threats - communism 50 years ago and Islamic radicalism today. To mainly deal with the communist threat, the British colonial government introduced, and it continues as law today, the Internal Security Act or ISA, which has as its main feature, the right of indefinite preventive detention without being charged nor tried in court.

Once a very controversial issue and heavily criticised by Western governments and NGO's, preventive detention has become grudgingly accepted as a necessary and hopefully limited violation of civil liberties, as these same governments try to combat terrorism in their own societies.

Post 9/11, the United States government in particular has embraced indefinite preventive detention. Recent terrorist events in Europe by their own citizens have even raised questions as to whether preventive detention should have been used more aggressively.

The debate therefore, has shifted in recent years from calls for outright abolition of the ISA and its equivalents, into the need to ensure that this unconstrained, extra-ordinary power does not become abused.

Lest anyone think that concern about potential abuse of the ISA implies a distrust of the current government and the PAP, we should remember that in a 50 year time horizon, it might well be a newly-elected, non-PAP government which might give cause for worry. Potential abuse resides in any government with unconstrained powers, regardless of political heritage or ideology.

Proponents for the abolition of the ISA argue that preventive detention can still be preserved under other legislation, such as an anti-terrorism act. My own sense is that if one accepts the principle of preventive detention, then whether we keep the ISA or replace it by a similar act, makes not much difference. My primary concern is that preventive detention must not be unconstrained and must have checks and balances which serve the legitimate purposes of security agencies whilst making abuse more difficult, if not entirely impossible.

For example, the right to detain a person for an initial one year period - possibly reduced from the current two years -- should remain unconditional and unconstrained.

However, subsequent detention periods could require a higher degree of external review than currently provided for - say, two high court justices rather than the current single judge and two persons appointed by the President. Failure to achieve unanimous approval for further detention would trigger a process of further review by for example, a non-partisan panel comprising members of the legislature. There could also be a cap on the maximum number of consecutive detention periods unless specifically approved by a similar legislative panel.

Such measures cannot fully prevent abuse by an all-powerful government, but in a parliamentary system with at least some opposition representation, truly national-security threats as opposed to opponents or critics of a ruling party, can be differentiated and abuses brought to public attention.

A society which allows preventive detention should be acutely aware of the risks this brings to its hard-won, much-cherished freedoms and civil liberties. It must reflect deeply on the need for a balance between a government requiring extra-ordinary powers to deal with extra-ordinary threats, and a civil society requiring space to freely express its views without fear of detention.

In the next 50 years, the search for this balance will be dynamic and changing as the threats to internal security will change. What must not change is the constant awareness that any people who surrender too much extra-ordinary powers to any government, does so at its own peril.

Civil Security

Let me now move to civil security, which deals with the relationship between the individual and the state on issues related to crime and punishment. My question here relates to the sustainability of various forms of punishment into the next 50 years as we become an increasingly affluent, mature, and presumably more compassionate, "civilised" and humane society. Can we modify and eventually abolish some possibly "cruel and unusual" punishments without sacrificing our notably low levels of crime?

What is appropriate punishment in one era may not be so in another period; indeed, the assumption behind the concept of "cruel and unusual punishment" in American jurisprudence is the notion that what constitutes cruelty and unusual-ness depends on current social norms. The practice of branding convicts on the cheek by hot irons was the norm in 17th century America or Europe but by the 19th century it would be considered cruel and unusual. The same for flogging and whipping.

To the extent that the duality of crime vs punishment reflects the values of a society, our 50th anniversary is a good time to reflect on how our evolving values will affect our criminal code.

I refer specifically to the practice of caning, which might have been the norm in the past century, but which would certainly be construed as cruel and unusual punishment in the First World, to which we apparently have arrived and want to remain in, at least in terms of wealth.

There are two different approaches in the arguments against caning.

First is the notion that it is by itself barbaric and should be abolished.

Second is the notion that even if one were to reluctantly consider this a necessary punishment for some offences, it should in some vaguely moral way be appropriate to the crime - that a physically injurious punishment should be restricted only to physically injurious offences.

This concession to retaining caning for violent crimes such as rape or grievous hurt has no basis in legal philosophy; but at least it meets the human desire for some kind of moral retribution, not unlike the Biblical injunction of an eye for an eye, a life for a life.

But even this concession would find unacceptable the practice of caning for offences such as spraying graffiti on public walls, or for money-lending by loan sharks, or for overstaying a visa. All these offences and more, now provide for caning.

What started out in colonial times as caning for hardened criminals and violent triad gangsters - who incidentally were not Europeans and therefore not worthy of the same humanity -- is now meted out for a very wide range of offences with little relationship to each other, except perhaps that they were social problems at the time and caning was seen to be the most effective deterrent.

Proponents of caning are not shy about the reason for its deterrent impact. It is intentionally brutal and painful. In a rare and candid account with The Straits Times, the Director of Prisons once gave a graphic account, parts of which I quote now:

"The prisoner, stripped of all his clothes, is strapped to a trestle by his ankles and wrists… Correct positioning is critically important. If he ( the person applying the caning ) is too near the prisoner, the tip of the cane will fall beyond the buttocks and… thus reduce the effect of the stroke.

If he is too far, the stroke will only cover part of the buttocks. Most of the prisoners put up a violent struggle after each of the first three strokes. After that, their struggles lessen as they become weaker. At the end of the caning, those who receive more than three strokes will be in a state of shock. …. Many will collapse, but the medical officer and his team of assistants are on hand to revive them and apply antiseptic on the caning wound. Many will pretend to faint but they cannot fool the prison medical officer whose presence is legally required. "

Interestingly, the colonial authorities practiced flogging by what is affectionately called a cat-o-nine-tails until 1954, when it was banned. Possibly caning might have been banned a few years later, but in 1959 the PAP took over the government and, indicative of the pragmatism for which it is highly vaunted, decided that what works, should simply remain. And so it has remained for 50 years, and as we moved from Third World to First World, and other countries banned vestiges of centuries past, we added more non-violent offences for which caning was the punishment.

Since we have placed deterrence as the sole reason for a punishment and have abandoned proportionality altogether, one wonders what offences we would NOT apply the cane to, if the offence became widespread enough. How about e-commerce crimes, which as the papers recently noted, has increased over 200 per cent in the past few years?

As I mentioned earlier, graffiti-spraying, moneylending, repeated drink driving, visa overstaying, were all added after independence. No new offences have been added in recent years, but neither were any removed.

The other egregious use of caning is for young people - something which might surprise most parents here. The minimum age for criminal responsibility is - guess - seven years old. Juvenile offenders between seven and 16 can be caned and put into solitary confinement; they can be imprisoned for life if under 18 years old and be tried in adult courts. Yet you can only vote at 21 years old; is the discrepancy between age of criminal liability and political maturity somewhat unbalanced ?

There is clearly no huge public demand for the end of caning or for that matter, for the abolition of capital punishment. To most Singaporeans it is a non-issue. As to whether it is truly a deterrent or not, most people do not really care. If caning helped get us to where we are today as a crime-free society, why abolish it?

Therefore, if our Government simply abolished caning, it would not be seen as responding to the desires of the public, and can even be considered irresponsible, if crime rates rise as a result of abolition. But for the sake of a more humane penal system, considering a future without caning is both a governmental as well as social imperative. Thus, a reasonable step a government can do is to impose a moratorium on caning, either selectively or as a whole, and measure whether the offences increase as a result.

For example, some believe that caning for graffiti-spraying was introduced in the 1960s because the Barisan Sosialis supporters painted politically incendiary slogans on walls and caning was introduced to stop them.

Whether that was justified or not, is for history to decide. But the likelihood of such forms of civil disorder recurring is not high.

Whether repeated drink driving will increase if offenders are not caned, I do not know, but we can easily find out and measure the consequences. The result should determine the next steps.

Over time and with the excellent law enforcement we have, I would hope that we can evolve into a relatively crime-free society without the need for punishments which belong more to centuries past and not centuries future. But if I am wrong, we can always end the moratorium.

The hallmark of a society progressively evolving towards higher standards of civilised behaviour is its ability and willingness to explore, debate and try out new ideas and test their efficacy. At this milestone of our national journey, we should have the moral audacity to question the sustainability of old ideas and aspire for a higher level of human development.

A moratorium on capital punishment follows the same logic as for caning. But it would be unrealistic to think that this will happen without first achieving a positive result from a moratorium on caning.

However, we can tighten the criteria for capital punishment so that offences such as causing death but simply intending to cause injury, being just involved in a group which has caused a death, do not incur the death penalty. As for drug trafficking, an end to the mandatory death penalty and giving more leeway to judges, which was recently implemented, is a step in the right direction.

The challenge will be to maintain the laudable public safety for which Singapore is famous, while also progressively reducing the physically injurious and ultimately lethal forms of punishment.

In the march of humanity towards civilisation, one consistent marker is how that society punishes its offenders and not just how it rewards its heroes.

Societal Security

I now come to societal security. The challenges to Singapore's societal cohesion has always been religious and racial cleavages. The PAP's fundamental approach to this security issue has been to vigorously promote a multicultural and multiracial society with very robustly articulated and consistently protected rights for every minority to practise its traditions.

No tolerance is allowed for any community, whether racial or religious, to infringe on, dominate or insult another. Instead of assimilation, where minorities are encouraged to jump into a melting pot and emerge as the same people, Singapore espoused integration, whereby people retain their racial and religious traditions but respect the rights of the other.

These policies have been widely lauded by all observers, and is no small achievement when contrasted against serious racial or religious cleavages in developed countries such as the USA, or for that matter, in France as we have recently seen. Singapore's commitment to racial and religious harmony and equality of opportunity for all communities, was never just an aspiration or ideal, but an imperative for survival.

But even with this laudable tradition, we can still do more to enhance social cohesion, especially at this juncture of history when new challenges also present new opportunities.

The opportunity is to gradually and carefully open up debate on the most sensitive racial and religious issues so that we achieve the full transparency, candour and mutual trust between racial and religious groups which marks a truly mature society, without the divisive tragedies of societies which allow totally free expression even at the risk of inflaming already volatile and emotional issues.

Singapore if it has erred at all, has been on the side of caution, so that the slightest discussion of anything potentially divisive in the realm of race and religion, is considered out of bounds. European nations have erred, on the other hand, in allowing such freedom of expression as resulted in the tragic Charlie Hebdo massacres.

I believe that erring on the side of caution is the right approach, but in the next 50 years we can gradually introduce more transparency and candour in the discussion of race and religion so that our societal security can flourish with fewer and fewer OB markers.

For example, ethnic quotas in HDB estates and mandatory ethnic representation in electoral constituencies are publicly known policies, but statistics and policies on the ethnic composition of the national service army and police are considered too sensitive for open discussion. Demographic data on new migrants are not openly available, but birth rates of different races in Singapore are public information. There seem to be inconsistencies on what is deemed sensitive or not, and what is confidential versus publicly available information.

It can be argued that the traditional fault lines of CMIO - Chinese, Malay, Indian, and Other - are transforming as new fault lines emerge.

The so called curry wars where Singaporeans of all races lined up against new citizens from China who objected to curry aromas from their HDB neighbours, illustrate that culture and race are intertwined rather than inexorably fixed along simplistic racial lines. The same may be true for Singaporean Malays versus those from neighbouring Indonesia and Malaysia. Policies based on presumptions of old fault lines may have to be revisited as we evolve.

Issues of identity shall be the focus of my final lecture, but my point here is simply that societal security requires us to eventually discuss openly the most sensitive issues of race and religion, even at the risk of courting controversy overseas, or bordering into communal politics at home. Sensitive issues are eventually desensitised when they are brought into the open and discussed responsibly and diligently by all members of society.

Another area of potential social divisiveness is our new male citizens. The likelihood of their increasing in numbers can only increase, not decrease, because in-migration has to bridge some of the gap between our declining TFR and a consistent if not growing, population. Yet there signs of resentment by our NSmen against new citizens who benefit from Singaporean nationality but need make no sacrifices to obtain their passports.

Adding salt to the wound is the fact that many employers prefer to hire new citizens because they have no reservist liability.

Measures to reward reservists do not really solve the problem because many NSmen see them as devices to buy off their disaffection.

Neither are Singaporean reservists asking that new male citizens past NS liability age, serve the full two years which they are required to do.

Most Singaporean reservists seem to simply want concrete demonstration of a willingness by new male citizens to sacrifice some of their time for their new homeland, and of a genuine desire to be more integrated into the lives of their new compatriots. Inflow of foreign talent is generally regarded positively by Singaporeans, but the issue is not just tolerance. It is about the integration of new citizens into Singapore culture.

This can perhaps be achieved by requiring all new male citizens of reservist liability age to undergo a three-month programme which need not require full residential training but would impart civil defence, para-medical and para-police training, and with annual reservist liability of a week or two for several years.

This would clearly not be favoured by those new citizens who only want the convenience of a Singapore passport and are willing to invest millions of dollars for it; it may in fact lead to a halt in such applications (which in my view is no bad thing).

But for those who genuinely want Singapore to be their home, the opportunity to integrate more into our society and be able to also say with pride they too, serve the country and sacrifice for it, such a programme may even be welcomed, provided that the disruption to their lives is not enormous.

In conclusion, Singapore can proudly celebrate its 50 years as a sovereign nation, with some of the best international standards for all its uniformed forces, for its public safety record, and its rigorous adherence to multicultural, multiracial tolerance and mutual respect.

Security in all its dimensions, is a blessing which has taken decades to create and can all too quickly crumble through neglect, carelessness, reckless disregard, or irresponsible changes.

Therefore we should be cautious about needless tinkering. At the same time, a willingness to change with the times, or indeed to ride on the crest of the tidal waves of history, can prevent the intellectual rigidity which weakens the sustainability of our society as a dynamic and evolving culture.

Unlike general political and economic issues which are subject to shorter time frames based on election and business cycles, fundamental issues concerning society and what values we stand for take longer to unfold and resolve as they require citizens and civil society to engage in discourse between themselves and with governing institutions. By starting this public conversation now, we can build the capacity for discourse and reasoning which should benefit those of you who will inherit this nation.

This is an excerpt from a speech on security and sustainability by Ho Kwon Ping, the first Institute of Policy Studies S R Nathan Fellow for the Study of Singapore. It is the third in a series of five lectures on Singapore's next 50 years.