UK, Australia Sign Geelong Treaty for 50-Year AUKUS N-Submarine Pact

The United Kingdom (UK) and Australia signed a Nuclear-Powered Submarine Partnership and Collaboration Treaty at Geelong, Australia, to operationalise bilateral defence cooperation for the next 50 years under AUKUS Pillar I. The agreement, also known as the Geelong Treaty, was signed by the Australian Deputy Prime Minister and Defence Minister Richard Marles and the visiting United Kingdom  Secretary of State for Defence, John Healey, on 26 July 2025. 

About AUKUS 

In 2021, the leaders of Australia, the United Kingdom, and the United States announced a new maritime security alliance named AUKUS. The alliance was viewed as an effort to enhance Australia's defence capabilities and counter China in the Indo-Pacific region.

It has two pillars 

Pillar I

• Supply and delivery of nuclear-powered attack submarines to Australia and the United Kingdom
• Australia will purchase three to five Virginia-class nuclear-powered attack submarines already in service with the US Navy from 2032 onwards.
• A new nuclear-powered attack submarine will be built in the United Kingdom for the Australian and the United Kingdom’s Navy.
• The United States will provide the technology for the new submarine, which will be of British design.

Pillar 2 

It calls upon all three countries to collaborate on their advanced capabilities in military capabilities, including long-range hypersonic missiles, undersea robotics and artificial intelligence.

Agreement Between Australia and the United Kingdom 

The agreement to build and operate nuclear-powered attack submarines is valid for a period of 50 years.

Both countries will collaborate in the design, build, operation, and maintenance of new fleets of nuclear-powered submarines for both Navies.

The submarine will be built in the United Kingdom,

The submarine will enter service by the 2030s for the U.K. and the 2040s for Australia 

The United Kingdom will assist Australia in developing the necessary infrastructure to operate and maintain the submarines and will also train Australian naval personnel.

US Positon on AUKUS 

United States has stated that it is reviewing the $239 billion Trilateral pact, which established the AUKUS (Australia, the United Kingdom, and the United States).

The Donald Trump administration is reviewing the AUKUS to determine whether it fits into its America First Policy.

The United States wants its allies to increase their defence budget to 3% of their gross domestic product(GDP) and increase their contribution to the defence partnership.

The United Kingdom has agreed to increase its defence spending to 3 % of GDP by 2029, while Australia is not willing to raise its defence expenditure to 3.5% of GDP as demanded by the United States.

If the Donald Trump administration does not support AUKUS, then it will be extremely difficult for the Australian and British governments to operationalise AUKUS.