Geelong: In a landmark defence development with long-term geopolitical implications, Australia and the United Kingdom have signed a formal 50-year treaty to jointly develop, construct, operate, and eventually decommission a new generation of nuclear-powered submarines under the AUKUS alliance. This unprecedented agreement marks the most significant bilateral defence collaboration between the two nations since Australia’s federation in 1901.
The treaty, signed in Geelong by Australian Defence Minister Richard Marles and UK Defence Secretary John Healey, is being described as a foundational pillar of the trilateral AUKUS pact, originally formed in 2021 between Australia, the United Kingdom, and the United States. This deal, dubbed the Geelong Treaty, is central to "Pillar I" of AUKUS, which focuses on undersea military capabilities and nuclear submarine technology sharing.
At the heart of the agreement lies the joint construction of SSN-AUKUS class submarines, an advanced fleet based on British submarine designs, enhanced with American technologies. These submarines are expected to be operational from the late 2030s onwards for the UK Navy and the early 2040s for the Royal Australian Navy. The vessels are intended to provide both countries with formidable undersea capabilities in an increasingly contested Indo-Pacific region.
This long-term cooperation covers the entire submarine lifecycle: from initial design to construction, operations, maintenance, and final decommissioning. The treaty provides the legal and structural basis for extensive collaboration in engineering, technology transfer, personnel training, and secure facilities management between the two nations.
The agreement is not only about defence it carries substantial economic weight. The UK expects to generate nearly £20 billion in exports over the next 25 years as part of this programme. Australia, on its part, has committed a whopping A$368 billion to the overall AUKUS initiative, which includes both infrastructure development and submarine construction across multiple decades.
Thousands of high-skilled jobs are expected to be created in both countries in fields such as defence technology, shipbuilding, cyber security, nuclear safety, and marine engineering. The signing ceremony was held at the future site of Australia's submarine construction hub in Geelong, underlining the city’s growing importance in the country’s defence industry ecosystem.
The announcement coincided with the ongoing Talisman Sabre military exercises, which feature more than 40,000 troops from 19 countries operating in Australian territory. This backdrop underscores the rising military cooperation among democracies and the strategic shift toward Indo-Pacific security.
However, this development also comes as the AUKUS agreement faces political scrutiny in the United States. The Pentagon, under a Trump-era review, is reassessing the feasibility and structure of the trilateral pact. Despite these tensions, both the UK and Australia reaffirmed their full commitment to the submarine project, viewing it as an essential long-term investment in global stability and deterrence.
For Australia, the Geelong Treaty is a significant stride in diversifying its defence partnerships beyond the U.S. while still staying aligned with the broader Western security architecture. For the UK, this is a reaffirmation of its “Global Britain” strategy seeking influence far beyond its immediate region and strengthening its presence in the Indo-Pacific.
Both countries are also increasing defence spending, with the UK aiming for 5% of GDP by 2035 and Australia targeting 2.3% within the next five years. This financial commitment is seen as vital to sustaining high-end military programs like AUKUS.
As the world enters an era of rising maritime tensions, cyber warfare, and technological arms races, the Geelong Treaty represents more than a defence pact—it is a blueprint for how like-minded democracies can pool their resources and expertise to build resilient, future-proof security frameworks.
This agreement, binding for five decades, sends a clear message: Australia and the United Kingdom are not only committed to each other’s security but are ready to lead in shaping the undersea warfare architecture of the 21st century.