The region must not take for granted the foundation upon which its economic advancement was built, a rules-based order that has built confidence and trust between nations, Australian Prime Minister Malcolm Turnbull said yesterday.
"Shaking that, disturbing that, puts a lot at risk," he warned.
At a time when the region is anxious about China's rise and its intentions, Mr Turnbull also had a message for the Asian power, saying it and other powers should respect the rights of other nations and not use their coercive powers to bully others.
In his keynote speech last night that kicked off this year's Shangri- La Dialogue, the Australian leader also urged the region not to be too quick to judge the United States' commitment to the region based on President Donald Trump's pulling out of the 12-nation Trans-Pacific Partnership trade deal in January and then the Paris accord on climate change this week.
"I am confident this administration will recognise, as its predecessors had, that the United States' own interest in the Indo-Pacific demands more US engagement, not less," he said.
He gave as indication of the US commitment to the region the early visits to the region by Vice-President Mike Pence, Secretary of State Rex Tillerson and Defence Secretary Jim Mattis.
On China, he noted that it "has gained most from the peace and harmony of our region and it has the most to lose if it is threatened".
He added that "a coercive China would find its neighbours resenting demands they cede their autonomy and strategic space, and look to counterweight Beijing's power by bolstering alliances and partnerships, between themselves and especially with the United States".
Mr Turnbull said "21st century China will best succeed by respecting the sovereignty of others and in so doing build a reservoir of trust and cooperation with its neighbours", adding that it could do so by curbing the "unlawful, reckless and dangerous conduct of North Korea". He was referring to Pyongyang's nuclear and missile tests in defiance of United Nations Security Council sanctions.
He borrowed a metaphor from the late prime minister Lee Kuan Yew in describing how big nations or big fish would eat smaller ones and the smaller ones would eat the shrimp in making his point that "might is not right".
He noted that "the waters in which the big fish, little fish and shrimp can swim freely and safely are ones in which the rule of law is respected and individual states do not use their coercive powers to intimidate or bully others".
He added that as China rises in power, it is vital that it and other powers respect the rights of others, that "the big fish respect the little fish and the shrimp".
Mr Turnbull also addressed the issue of terrorism, noting that Islamist terrorist organisations including Al-Qaeda and the Islamic State in Iraq and Syria are very active in the region as demonstrated in the recent bombing in Jakarta and the large-scale attacks in Mindanao last week.
As more fighters battle-hardened and trained sought to return from the Middle East, there was a need for transnational collaboration including the sharing of intelligence.
Turning to Asean, he noted the grouping's success and said he supported a strong, united Asean that "continues to convene and strengthen organisations such as the East Asian Summit, the region's only leaders-led forum that can help manage the region's strategic risks".
The Shangri-La summit this year is held at a time of great uncertainty as the region faces a more assertive China that is challenging the primacy of the US, which appears to be in retreat from the world.
Today, Mr Mattis will speak at a plenary session.