Australia could face conflict long before the delivery of nuclear-powered submarines, say experts, warning the nation to evolve its defence strategy.
The Australian Strategic Policy Institute said Australia must adapt to manage a "looming period of strategic risk" ahead of the first submarines arriving in the early 2030s.
Australia is set to buy Virginia-class submarines from the United States in the early next decade, before a class of nuclear vessels is co-designed with the United Kingdom as part of an AUKUS agreement.
The submarine pact has attracted fierce criticism for its multi-billion-dollar price tag and questions over whether the US would hold its end of the bargain, with production timelines slipping and the Trump administration interrogating the contracts.
In a bleak report published on Wednesday, the institute raised concerns about Australian "deterrence gaps" that would leave it without enough firepower to counter potential adversaries like China, Russia, Iran and North Korea.
The medium-term acquisition of AUKUS submarines is irrelevant to the short-term problems facing Australia over the next few years, its report warned.
"That's because the first AUKUS submarines — US Virginia-class boats — won't be delivered until 2032, while the purpose-built SSN-AUKUS won't arrive until the early 2040s," the institute said.
"We can't, in effect, solve a 2027 deterrence problem with a 2032 deterrent capability."

A report warns acquiring submarines in the medium term will not deter threats faced in the meantime. Source: AAP / Colin Murty
These methods lie outside of usual military war-fighting and include tactics that operate indirectly against an adversary's vulnerabilities.
It could also involve working with regional partners to resist coercion and political interference while building domestic capability across cyber security, electronic warfare and space technology.
Australian Industry and Defence Network CEO Mike Johnson said sovereignty is about security, as well as economic resilience and technological leadership. He will share his vision at the National Press Club in Canberra on Wednesday.