Small countries like ours have constantly to ask ourselves: How can we make sure that we survive, and keep our place in the sun?

Going by the rhetoric of diplomacy, international relations are based on high-minded principles... but in practice, the conduct of international affairs reflects a harsher reality. It is power that determines which countries prevail, and set the agenda. Realpolitik is never absent, even if it is not quite the law of the jungle.

Perhaps that is why the Chinese say "small states have no foreign policy"; they cannot shape events, but have to take the world as they find it. Look at what happened when Iraq invaded Kuwait and Russia annexed Crimea.

Singapore, small as we are, has refused to accept this as our fate. We are determined to be masters of our own destiny. Our foreign policy is a balance between realism and idealism. We know we have to take the world as it is and not as we wish it to be. But we believe that we can and must defend ourselves and advance our interests.

Of course, we have to be clear about our fundamental interests, which have not changed in the last 50 years:

• To have peace in the world, to have an international order where countries respect and abide by international law.

• To establish a network of friends and allies whom we can work with.

•Ultimately, to preserve our sovereignty, and our right to determine our future.

How can Singapore advance these national interests? There is a saying from the Confucian classic Great Learning: "One must first cultivate one's own person, then regulate one's family, then order well one's state, then only can one make the whole kingdom tranquil and happy."

This is the Confucian view of government, and is deep in the Chinese psyche, and a timeless piece of wisdom which holds universal application, that there is a direct link from the virtue of the individual, to the family, to the larger society and to universal harmony.

Singapore is a modern society, but we have tried hard to maintain traditional values that are relevant to us and this quote neatly encapsulates one way to think about how we advance our interests internationally. We must first put our home in order, so a successful foreign policy is linked to what we do domestically in Singapore.

I will elaborate on this, starting from the outside.

First, internationally, we have to be an active, constructive player, seek to add value and make ourselves relevant to other countries. Second, in our own region, we have to make common cause with our neighbours. Third, Singapore must continue to succeed as a nation to wield any influence at all. Fourth, Singapore's success, whether externally or domestically, depends on our staying united as a people, firm in our conviction that Singapore will endure and prevail.

CONSTRUCTIVE PLAYER

Diplomacy covers many issues, and takes place in dozens of fora. As a small country, we cannot be everywhere but we have to be present for the key ones - for example, United Nations, World Trade Organisation, Apec - where our interests are at stake.

We must have the strategic sense to maintain our policy and direction over many years, to secure our interests patiently and subtly. At the same time we have to be tactically nimble during these conferences, to influence discussions where we can, and where it is important to us.

What do we do? First, we make common cause with others, in particular with other small states. Individually, our voices may be small but, collectively, our voices are amplified. That is why we set up the Forum of Small States at the UN, an informal group of 105 small countries.

Second, we constantly look ahead to anticipate developments, so that we are positioned to protect our interests, whichever way events may break. That is particularly important in these uncertain times. For example, the third G-to-G project between Singapore and China in Chongqing positions us at one end of the "One Belt, One Road" project. This now makes us part of the "belt" passing through Eurasia as well as the "road" passing through South-east Asia.

Third, we bring something to the table. We do not have deep pockets of money to disburse nor power to coerce others but we master the issues, we bring constructive ideas, and every single diplomat in our team adds something to the discussions.

This is what we did a generation ago, when the UN Convention on the Law of the Sea (Unclos) was being negotiated. Professor Tommy Koh, our Ambassador-at-Large and veteran diplomat, played a central role in the negotiations as president of the conference. We formed a coalition of landlocked and geographically disadvantaged nations to push for our common interests. As a small island state that has always depended on maritime trade as our economic lifeline, we had to defend the rights of freedom of navigation and overflight.

The Unclos treaty provided for these rights, and has become an important legal reference point for claims over sea areas, and the types of activities permitted in these sea areas. Unclos strikes a careful balance between the rights and interests of littoral states and those of other countries in the community of nations, helping to provide a way of resolving disputes peacefully.

Currently, we are similarly actively engaged in the negotiations on climate change, including the major meeting in Paris next week. Singapore is hardly a major emitter of greenhouse gases - even if we all stopped breathing, it would not make any difference to global warming. But our ambassadors for climate change have played active roles lobbying for support and acting as a bridge between developed and developing countries.

Occasionally, we are lucky enough to take a small initiative which leads to a more significant outcome, for example the Trans-Pacific Partnership (TPP). It started out 10 years ago, when four small countries concluded the Pacific 4 (P4) free trade agreement - Brunei, Chile, New Zealand and Singapore. Trade with each other was modest. Together, the impact on world trade was negligible. But we did the P4 in the hope that it would form a nucleus which other Asia-Pacific countries could later join and which would develop into a significant free trade arrangement in the Asia-Pacific. This is what in fact happened.

More countries wanted to be a part of this. Eventually it became the TPP, which is a grouping of 12 countries comprising 40 per cent of global GDP, including the US and Japan. The TPP is completely different, in scale and ambition, from the P4. Its significance is not just economic, but also strategic. It deepens ties between the US and Asia, makes for a more integrated and stable region, and is a pathway to an eventual Free Trade Area of the Asia-Pacific.

REGIONAL STABILITY

Second, we work to sustain good relations amongst countries in our immediate region, namely South-east Asia. Asean is the cornerstone of our foreign policy. We work actively with our Asean partners, we participate in Asean projects, we help the less developed countries in Asean - countries like Cambodia, Laos, Vietnam and Myanmar - to narrow the development gap through the Initiative for Asean Integration. We work hard to forge Asean consensus on common issues, whether pursuing Asean economic integration, or tackling transboundary haze.

Singapore is one of the smaller countries. We are not in a dominant position, but we do our part. We also work with our Asean partners to make Asean an effective and credible player in wider regional or multilateral forums.

Asean diplomacy is not always about enhancing cooperation. From time to time, we also have to manage disputes and frictions, as we are doing on the South China Sea. Singapore is not a claimant state, but we do have important interests at stake - freedom of navigation, peaceful resolution of disputes, respect for international law. We also have a role to play because we are the coordinator for Asean-China Dialogue Relations. We aim to be an honest broker, dealing fairly and openly with all parties so that we not only preserve stability and peace in the region but also establish our reputation for being a reliable country to deal with, and Asean can enhance its credibility as an effective organisation that can deal with difficult security issues.

Within Asean, our most intense relations are with our closest neighbours, Malaysia and Indonesia. In Kuala Lumpur last week, PM Najib (Razak) and I opened Titian Budaya, a joint celebration of 50 years of Singapore-Malaysia friendship through art and culture. In my speech, I described our relationship using the Malay proverb, Bagai aur dengan tebing - "Like the bamboo and the river bank", each depends on the other for their mutual survival. Singapore and Malaysia depend on each other, and we must work with each other. So Singapore works hard to strengthen our ties with Malaysia and Indonesia. They are among our biggest economic partners.

SINGAPORE'S SUCCESS

Third, an active and successful foreign policy depends on whether Singapore is successful as a country. This means a prospering economy, the people living in peace and harmony and the country well-run and, in particular, safe, able to defend ourselves, and determined to do so.

A failed state cannot have an effective foreign policy. No one will take it seriously. Because our economy has prospered, others want to do business with us. Our society lives in harmony, and we have found solutions to many of our problems, like housing, healthcare, or water supply. Hence others hold us in high regard and find us an interesting example from which they hope to glean ideas. That is why we can cooperate with many countries on projects that capitalise on our expertise and reputation, which creates opportunities for our businesses and people.

We have government-to- government projects in China - Suzhou Industrial Park, Tianjin Eco-City and, now, Chongqing. We have joint venture industrial parks in Indonesia, Vietnam. Our companies are master-planning Amaravati, the new capital of Andhra Pradesh state in India.

But diplomacy has to be backed by something more than words. Words are indeed important. Singapore takes words very seriously. We weigh every word in the statements we issue, we honour every agreement that we enter into, and we expect the same of others. But, ultimately, words have to be carried out and realised in actions and outcomes.

Therefore, it is important for us to have a strong defence, so as to protect Singapore when all else fails. Hence a strong, capable Singapore Armed Forces is a vital layer in our external policy.

Singapore has been a successful country, but we must never let that go to our heads. We must never believe that we are superior to others or that we know better than others how to solve their problems. Just as others hope to learn something from us, we too must always be eager to learn from others.

ONE UNITED PEOPLE

Fourth, to be successful, we must stay as one united people, united politically, and united as a cohesive, multiracial society.

We have to be united politically. This does not mean no political opposition. It means that citizens vote in open elections for who they wish to run the government, the opposition understands Singapore's fundamental interests in the world and does not seek to undermine them to gain political points or court foreign support, and we all come together after elections, especially when dealing with other countries.

We have had opposition parties like that. Mr Chiam See Tong for example: Whatever our domestic disagreements and arguments and policy perspectives, when he travels overseas, he stands up for Singapore and closes ranks. And that is really the norm that should prevail in politics in Singapore.

It is important for us to maintain a clear direction and understanding of our national interests, and to pursue that consistently over a long period. It can help to compensate for our lack of heft, give confidence to others that we will be reliable partners. In a country where the politics is fractious, as the political wind changes, so often too does foreign policy. This makes it much harder for others to work with it, as they cannot be sure that the next government will continue to pursue the same policy. It also makes it easier for others to take advantage of uncertainty and wait you out, knowing that your government will not last.

We also have to be united regardless of race, language and religion, in order that we are not divided when we conduct foreign policy. We may be Indian Singaporeans, Malay Singaporeans or Chinese Singaporeans, but we are above all Singaporeans first. We have to see the world through Singaporean eyes and advance Singapore's interests as our common interest.

There are ties of culture, race and kinship between our ethnic groups and corresponding groups in India, China or South-east Asia. Similarly with our religious groups, whether Hindu, Christian, Buddhist or Muslim. These ties are an advantage, because they help us to understand and work with partners in China, India, South-east Asia or the Middle East. Yet they can also be a vulnerability, if external ethnic or religious pulls can split us along the fault lines.

So we have to keep working at our racial and religious harmony, and keep strengthening our shared Singaporean identity. We are a much more cohesive society and we have a much stronger Singapore identity now. We are very careful in our ties with other countries, where race or religion can lead to misunderstanding. Take, for example, our relations with China. We enjoy very good relations with China but it is quite clear that we are Singapore, they are China and we are different. When Singapore leaders meet Chinese leaders in formal meetings, we speak in English and use interpreters, even though many of us understand and can speak Mandarin.

Other countries may not realise this, and may think that because many Singaporeans are of Chinese descent, so Singapore is a Chinese society. But the distinction is critical for us, as a multiracial society.

A SHARED CONVICTION

In the end, both our external influence and our domestic success come down to us as individuals. We must be determined that we want to be Singaporean, to stand up in the world, and to be a shining red dot. Mr Rajaratnam said: "Being Singaporean is a matter not of ancestry, but of choice and conviction." If we have that conviction, the rest will follow.

Others are watching us too, to see whether Singaporeans have that conviction, whether we have fight and we have heart. It shows in the spirit of our soldiers, those serving their national service full-time, and those in NS units, our will to fight for what we cherish and believe in.

It shows in how we help one another and our neighbours. For example, during the haze, volunteers from Relief.sg and Let's Help Kalimantan travelled to Kalimantan and Sumatra multiple times to deliver masks to the locals. They worked alongside international organisations and the Indonesian government, and brought about change in a small but tangible way.

Yes, we defend our corner, and care for our own people, but our people are not narrow-minded. We show a generosity of spirit, and we are compassionate towards others.