Australia will host USS Colorado, the first U.S. nuclear-powered attack submarine under the AUKUS (Australia-UK-U.S.) defense pact, strengthening military cooperation among the three allied nations.
The deployment marks a step toward establishing a regular American submarine presence in the country and expanding the three nations’ collective deterrence capabilities in the Indo-Pacific. The agreement aims to strengthen Australia’s naval capabilities while deepening defense ties with the United States and the United Kingdom.
The move comes amid growing regional security concerns over China’s military expansion and reflects the allies’ efforts to maintain a strategic balance in the region.
Expands submarine presence
Australia will host the USS Colorado, a U.S. Navy Virginia-class fast-attack submarine, from late 2027 as the three AUKUS partners expand their undersea warfare capabilities.
The deployment will establish the first submarine assigned to Submarine Rotational Force-West (SRF-West), a planned rotational force based at HMAS Stirling in Western Australia.
The arrangement is designed to strengthen submarine operations in the Indo-Pacific while helping Australia develop the technical expertise and infrastructure required to operate and maintain its own nuclear-powered submarines. It will also expand regional maintenance and support options for American and British submarines.
The USS Colorado (SSN 788) is a 115-meter (380-foot) Virginia-class fast-attack submarine designed for undersea warfare, surveillance, and land-attack missions. It carries land-attack missiles and sophisticated torpedoes, giving it capabilities to engage targets both underwater and on land.
The U.S. Navy commissioned the submarine in March 2018. Its assignment to SRF-West represents a significant step in establishing a regular rotational presence of American nuclear-powered submarines at an Australian naval facility.
Under the plan, HMAS Stirling will eventually host up to four U.S. fast-attack submarines and one British fast-attack submarine on a rotational basis. The submarines will not be permanently based at the facility but will rotate through it as part of the three countries’ broader defense cooperation.
The deployment will also build on Australia’s preparations to support allied submarines. A U.S. Submarine Maintenance Period is scheduled to begin later this week, demonstrating the country’s growing capacity to sustain American and British nuclear-powered fast-attack submarines.
Australian Deputy Prime Minister and Defense Minister Richard Marles said the initiative was on track, with American personnel already at HMAS Stirling preparing the site.
Boosts sonar production
SRF-West aims to help Australia develop the expertise and infrastructure needed to operate, maintain and regulate its own nuclear-powered submarines. Although the submarines will carry conventional weapons, their nuclear propulsion systems require specialized technical skills, trained personnel and dedicated facilities.
The rotational force will also expand maintenance options for AUKUS partners, supporting submarine deployments and helping sustain advanced undersea platforms in the Indo-Pacific. Australia’s wider submarine program could cost up to U.S. $235 billion over 30 years, according to government forecasts.
The three partners said SRF-West activities would comply with their international obligations, including the Treaty on the Non-Proliferation of Nuclear Weapons. Australia will also adhere to the South Pacific Nuclear Free Zone Treaty, known as the Treaty of Rarotonga.
Meanwhile, Australia is strengthening its domestic naval technology industry. French defense group Thales has opened a sonar facility in Rydalmere, western Sydney, to manufacture and maintain towed-array sonar systems for military submarines, ships and other maritime platforms.
Jointly funded by Thales Australia and the Australian government, the facility will supply sonar systems for Hunter-class frigates, Collins-class submarines and the BlueSentry autonomous system. Towed-array sonar uses sensors deployed behind a vessel to detect and track underwater acoustic signals, supporting maritime surveillance and submarine detection.
Local production and maintenance are expected to reduce reliance on overseas facilities, shorten offshore servicing periods and extend deployment times.
Thales owns approximately 35 percent of Naval Group, the French defense contractor that lost Australia’s submarine contract in 2021 after Canberra canceled the program in favor of AUKUS.