The United States has formally established an administrative framework for a military presence in Western Australia, signaling a significant expansion of its submarine-related operations near Perth. The US Navy quietly created Naval Support Activity (NSA) Stirling in late May to provide services for deployed personnel, contractors, and their families at the HMAS Stirling naval base. This designation matches terminology used at some of the Navy’s most strategic overseas installations.
According to US Navy officials, the deployment at the Western Australia facility, part of the broader Submarine Rotational Force West (SRF-W) initiative, will grow substantially in coming years. While the Australian government has previously cited around 1,200 American and British personnel involved, a US Navy spokesperson indicated that by 2030, the number of Americans alone supporting the mission will reach approximately 2,300. This count includes sailors, civilian employees, contractors, and family members.
The establishment of NSA Stirling follows a two-year planning process initiated with Australia's approval and invitation, according to Vice Admiral Scott Gray of the Navy Installations Command. The facility will offer administrative support, healthcare, housing, and family services to US personnel, aiming to bolster force readiness for "enduring" submarine deployments. Admiral Gray emphasized that the base’s creation supports the Navy’s broader mission to back the fleet, warfighters, and families.
The expansion also includes the planned reactivation of Submarine Squadron 3 at HMAS Stirling, forecast to host up to four US and one British Virginia-class submarine from next year. These developments form a key early phase of the $368 billion trilateral AUKUS security partnership between Australia, the United States, and the United Kingdom.
Despite these upgrades, the Albanese government has maintained that the US presence is not a permanent foreign base on Australian soil. However, some analysts note that the US Navy’s classification of NSA Stirling aligns with characteristics typical of a military base. Elizabeth Buchanan, senior fellow at the Centre for the National Interest in Washington D.C., described naval-support activities as shore facilities with full military base features.
Australian officials have at times provided mixed messaging about the SRF-W commitment. Defence Industry Minister Pat Conroy initially described the deployment as a five-year arrangement ending in 2032, coinciding with the expected arrival of nuclear-armed submarines. Yet subsequently, Conroy, Defence Minister Richard Marles, and the US Department of Defense affirmed the arrangement would be enduring.
The scaling up of the US Navy’s presence in Western Australia highlights the strategic prioritization of the Indo-Pacific region under AUKUS and the broader US commitment to sustaining naval capabilities alongside allied partners. NSA Stirling now joins other significant overseas naval support activities, such as those in Bahrain, Naples, and Crete, cementing its role within the US’s global military infrastructure.