SINGAPORE - The question of trust is the more fundamental issue in the ongoing debate and tussle over the world's next 5G networks given the need for countries to have confidence in the security of the systems, said Prime Minister Lee Hsien Loong on Friday (May 31).

Beyond technical considerations that Singapore is mulling over in its own decision, he said the lack of trust could lead to grave consequences where countries end up developing their own systems and operating in separate worlds that are less safe and more unhappy.

PM Lee was speaking during a question-and-answer session at the Shangri-La Dialogue, after delivering the keynote address at the annual security forum.

He was asked the question by Mr Shawn Ho, an associate research fellow at the S. Rajaratnam School of International Studies, on whether Singapore shares Malaysia's view on Chinese technology giant Huawei, and if Singapore will be using Huawei for its 5G network.

Malaysia's Prime Minister Mahathir Mohamad had said in a conference in Tokyo on Thursday (May 30) that Malaysia was too small to have an effect on a huge company like Huawei.

"So we try to make use of their technology as much as possible. Yes, there may be some spying, but what is there to spy in Malaysia? We are an open book. Everybody knows," he said.

Earlier this month (May), the United States blacklisted Huawei - which it accuses of aiding Beijing in espionage - and has restricted the company's dealings with US companies.

On Friday, PM Lee said that Singapore is in the process of selecting its 5G system and equipment, with the decisions to be made "in due course".

He noted that other than resilience and security, there are other factors to consider, such as performance, cost, reliability, growth potential, and vendor diversity.

It is "quite unrealistic" to expect 100 per cent security from any telecommunication system, he said, and it does not matter whom the system is bought from, with every system having its own vulnerabilities.

But beyond the technical aspect, there is also the question of trust, which is the more fundamental issue, said PM Lee.

"Because if I don't trust the vendor, then I can inspect his software, I can test his system, I may find no bugs there, and I still cannot be sure, because there may be no bugs there today, it may be very well hidden or it may not exist," he added.

"But with every update which comes, something changes and how do I know where I will stand down the road during the contract?

"So I need to have trust in order to use the system. And if I suspect that you will abuse my trust, to compromise my systems, I will not be able to do business with you."

But there are grave consequences when going down this road, he said, describing it as a "very serious problem".

"Because if I don't trust your system, you are not going to trust my system, and then the chips... the software... the firmware and then the whole supply chain. And then you are in your world and I am in my world.

"And that is fundamentally a different kind of world from the one which we have been building in the last 30, 40 years since the fall of the Berlin Wall," he said.

But the problem of trust is a very difficult one to solve because there is anonymity on the Internet, and this means the incentive for players to behave themselves is considerably diminished, said PM Lee.

"If you look around the room, everybody denies doing this, and yet if you look around the room, everybody says I have a very serious problem with cybersecurity, with intrusions.

"Who are these people? Well, if you study it, they say there are multiple actors, and including state-sponsored actors. Which state, which sponsors, don't know."

PM Lee said that in the long term, there is a need to establish rules, such that responsibility can be pinned down, leading to restraint.

"For immediate decisions on the 5G systems, I think each country will have to weigh the options, there's the uncertainties, and will have to make its own choice."

During the question and answer session, PM Lee was also asked what small countries can do to avoid taking sides.

He replied that these countries should try their best to be friends with both the US and China, and to maintain relationships with both, and to develop ties, such as in economic, trade, and diplomatic relations.

"But to actively avoid taking sides actually also requires actively not being pressured to take sides," PM Lee said, to chuckles in the audience.

"And unfortunately, when the lines start to get drawn, everybody asks: Are you my friend or not my friend? And that makes it difficult for the small countries.

"We must expect sometimes to be asked these questions, and the answer is: Well I am friends with you, but I have many friends and that's the way the world has to be. And if it were not, I think it would be a much unhappier world."

Answering another question - on what Chinese leaders can do to put other Asian countries at ease - PM Lee acknowledged that while it may be hard for "one big country to choose another big country as a role model", there were lessons to be gleaned from the US' presence in Asia in the last seven decades.

He said the US has made many friends in the region, with its breadth of spirit, generosity and honesty, creating an environment that has made it possible for even "those who are not quite so close" to grow and prosper and compete in peace.