The Association of Southeast Asian Nations (ASEAN), an 11-country forum whose members stretch from Myanmar to Indonesia, is ill-equipped to handle security issues almost certain to cause trouble at home, according to the Lowy Institute paper.
The potential crises include war over Taiwan, a blockade of the Strait of Malacca - a key shipping choke-point, tension in the South China Sea and submarine cable sabotage among others.
"When the rubber hits the road, ASEAN is not effective at responding to crises, given the many cooks in the kitchen," the report's author Hunter Marston told AAP.
The organisation, which accounts for about seven per cent of global GDP and nearly 700 million people, was lumbered with competing national interests with few ways to co-ordinate in a crisis, Dr Marston's report said.
"ASEAN is like a ring, but at the centre is a hole rather than something substantive," he said.
"Strategic trust and co-ordination are what is lacking."
Observers have looked on particularly anxiously as the US and China beef up military presence around the Strait of Malacca, theorising it could close if a nearby conflict boils over.
Shutting it would cripple oil trade to Singapore, Australia's largest single source of refined fuel, deepening a supply crisis caused by conflict around the Strait of Hormuz and the Bab el-Mandeb passage at the entrance to the Red Sea.
And while closing the Strait of Hormuz knocked out a thoroughfare for about a fifth of the world's seaborne oil, the Strait of Malacca carries a substantial 45 per cent.
Most European-Australian trade also passes through the narrow conduit, along with significant volumes of goods from the Middle East and coal exports to India.
"Tensions in the South China Sea could spill over to cause other countries to make a difficult choice to prevent access," Dr Marston said.
"Freedom of navigation in the South China Sea, the Strait of Malacca and maintaining open sea lanes and lines of communication are essential for Australia's survival."
ASEAN partners Singapore, Malaysia and Brunei inked crucial fuel and fertiliser provision agreements with Australia in April, when the war in Iran threatened supply.
Australia is ASEAN's oldest "dialogue partner," but Canberra acquiring nuclear submarines under the AUKUS agreement has alarmed some of the organisation's fully-fledged members, particularly Indonesia, according to Dr Marston.
"That casts a long shadow across Southeast Asia."
Australian and ASEAN-member militaries have collaborated on war games, including one wrapped up on Saturday in the Philippines.
Defence Minister Richard Marles also hosted high-level meetings with his Malaysian counterpart with an ASEAN backdrop in Victoria on September 18.
Dr Marston stressed while Canberra was working "very hard" to assuage worried neighbours' concerns, trust in Australia among the bloc's members remained mixed.
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