This year will be one of "even more tensions" between the rising states of South-east Asia and major powers such as China and the United States, said regional security expert Malcolm Cook at the Regional Outlook Forum yesterday.
The forum, the flagship huddle for the ISEAS - Yusof Ishak Institute think-tank, is in its 20th year. It drew 600 people, including civil servants, academics and students.
The three main sources of regional tensions, said Dr Cook, 46, were China's increasingly "assertive and aggressive" stance towards its neighbours, the differing views among Asean members on Beijing's claims to the South China Sea and worries about United States President-elect Donald Trump's actions towards China and the rest of Asia.
In his presidential campaign, Mr Trump had called the region's coveted Trans-Pacific Partnership (TPP), brokered by his predecessor Barack Obama, "a potential disaster for our country" and vowed to nix it when he takes office on Jan 20.
Dr Cook, an ISEAS senior fellow, contrasted Mr Trump's unsettling behaviour with that of Mr Obama, who he said assuaged South-east Asia's concerns soon after his inauguration in 2009 by committing to maintaining the US' "longstanding, stabilising" presence in the region.
Traditionally, Dr Cook pointed out, South-east Asian countries had engaged with major powers such as the US and Japan "to keep them at a distance" so these powers could not make decisions for the region.
"You can't do that with China, though," he stressed. Dr Cook pointed to how China has generally replaced its "smile diplomacy" with a "sometimes snarling" approach since 2008, as it tried to stamp its claim over much of the South China Sea, where five Asean members have competing claims.
A clear example of China's increasing aggression, he said, was its denial of the Permanent Court of Arbitration's ruling on July 12 last year that held its claims, vis-a-vis the Philippines, to be unfounded in international maritime law.
In an interview with The Straits Times last Friday, Dr Cook said that under President Xi Jinping, China had the long-term goal of becoming the undisputed power around which other Asian states shaped their foreign policies.
On the one hand, he argued, China has made use of carrots, such as its flagship initiatives, the Asian Infrastructure Investment Bank and Mr Xi's One Belt, One Road bid for cross-border growth.
On the other hand, it puts pressure on its Asian neighbours to "stay quiet" on the arbitration ruling. This has created tension within Asean, with members unable to come to a united response to Beijing's stance on the South China Sea.
If China becomes Asia's paramount power, Dr Cook said yesterday, it would relegate the US and Japan to "destabilising interlopers" in the region. He noted that Indonesian President Joko Widodo and Philippine President Rodrigo Duterte were now "playing Japan against China to get billions of dollars in investments".
All that was unlikely to make the region a "geopolitical sweet spot".
Attending the forum was Mr Daniel Lau, 44, an engineering sales manager, who said: "(Dr Cook) was very clear.
"But it's just nine days into the new year, so we will have to play by ear the uncertainties ahead."