Singapore, being a small state, will face increasing pressures to take sides from the major powers in the region - the United States, Japan and China - as they adjust their three-way relationship and as the South China Sea has become a "proxy" in that adjustment, Foreign Minister K. Shanmugam said.
China's long-term objective is to be the dominant power in East Asia, noted Mr Shanmugam, who is also Law Minister, at a Singapore Press Club talk yesterday.
It "makes no secret" of its desire to exclude the US from the region, he said, pointing to Beijing's new mantra of "Asia for Asians".
But the US, the current dominant and resident power, does not like being challenged, he noted.
Added to this rivalry is Japan, a security ally of the US with its own complex relationship with China and its desire to play a more active role in the South-east Asian region in response to a rising China.
China is working towards its objective chiefly by building economic linkages with countries in the region, including its One Belt, One Road initiative and the setting up of the Asian Infrastructure Investment Bank (AIIB).
While Singapore enjoys good relations with China as well as Japan and the US, "I'm not sure if we have the luxury of space as we had in the past of being friends with everyone", said Mr Shanmugam.
In the next few years, "because of their competition, they, as major powers are wont to do, will soon be talking to us in terms of 'either you're with us or against us' ".
But it has also escalated the pace of reclamation in the South China Sea. While other claimant states have also built facilities on the disputed islands, a recent Pentagon report said some 1,200ha had been added since last year, so that in 20 months, China has reclaimed 17 times more land than all other claimants had in the last 40 years.
Neither have the Chinese denied that they will place military features on the reclaimed land, for example, a runway on Fiery Cross Reef. "There can be no doubt that China's build-up is to achieve the capability to control sea lanes in the South China Sea," he said, adding that China probably would not block commercial maritime traffic.
In naval terms, the Chinese are far behind the Americans, but they do not like US ships coming so close to their territory, so they are relying on the concept of deniability, hesaid. Having missiles and other military installations on these land features would give serious pause to any US naval commander.
However, this has got the Americans concerned about freedom of navigation and access for its navy, and they have been reacting by sending reconnaissance planes very close to the reclaimed islands.
Singapore, he noted, had been calling for the dialling down of tensions that have risen as a result of the increased rivalry between the major powers in the region.
And while Singapore enjoys good relations with China as well as Japan and the US, "I'm not sure if we have the luxury of space as we had in the past of being friends with everyone", said Mr Shanmugam. In the next few years, "because of their competition, they, as major powers are wont to do, will soon be talking to us in terms of 'either you're with us or against us' ", he said.
He noted earlier in his speech that the US had tried to stop Singapore from supporting the AIIB, citing concerns over its governance, but Singapore was one of the first countries to support it because there was a need for capital to build the region's infrastructure.
He said Singapore's response to the major powers would be that the Republic would act in its interests.
However, Singapore, being small and dependent - including on the US for defence technology, and on the Chinese and Japanese for trade and investment - will "always be subject to pressure". "We're going to come into an even more interesting phase of our foreign policy where I fully expect that we will be subjected to far more pressure than we have been, and it's going to require fairly adroit diplomacy and the strength and willpower within Singapore (to overcome it)."
The core of Singapore's diplomacy is having a strong defence, he noted. But Singapore has also built regional mechanisms like Asean to maintain peace and resolve disputes. At the global level, it has tried to create a huge footprint through taking an active role in various United Nations-related organisations.
Nearer home, Singapore has good ties with its two closest neighbours, Malaysia and Indonesia. However, the increasing Islamisation in Malaysia and nationalism in Indonesia bear watching, he said.