The establishment of Naval Support Activity (NSA) Stirling, off the coast of Perth in Western Australia, is seen as a major step in the AUKUS (Australia-UK-US) partnership. The facility is designed to provide comprehensive support services for US personnel and their families stationed at HMAS Stirling.The initiative is central to the Submarine Rotational Force-West (SRF-West), which will host US and UK nuclear-powered attack submarines on a rotational basis. The base is located south of the Lombok and Sunda Straits, two of the alternative maritime access routes used by China to reach the Indian Ocean, with the Strait of Malacca remaining the primary passage.AUKUS, announced in September 2021, aims to promote a free and open Indo-Pacific. The partnership is widely viewed as a response to China’s growing assertiveness in the region, although Beijing has criticised the grouping, describing it as a destabilising force.The agreement is structured around two pillars. Pillar I focuses on Australia’s acquisition of nuclear-powered submarines and the rotational deployment of allied submarines in the country. Pillar II centres on collaboration among the three nations in advanced technologies, including undersea capabilities, quantum technologies, artificial intelligence, cyber warfare, hypersonic weapons and electronic warfare.Initiated in 2024 under the US Navy’s Japan region, NSA Stirling is scheduled to become fully operational by 2027.Australia is already investing heavily in the programme, allocating AUD 8 billion for infrastructure upgrades at HMAS Stirling, AUD 3.9 billion for a new submarine construction yard and AUD 12 billion for the Henderson defence precinct.These investments are intended to strengthen Australia’s capacity to operate and maintain sovereign nuclear-powered submarines while streamlining the acquisition of Virginia-class submarines.According to the Australian Broadcasting Corporation (ABC), the Royal Australian Navy (RAN) will receive three second-hand Virginia-class nuclear-powered submarines from the United States. Earlier plans envisaged the transfer of two used submarines and one newly built vessel.The submarines now expected to be delivered are Block IV variants of the Virginia class, which entered service in 2020.The United Kingdom has also reaffirmed its commitment to the partnership, with HMS Anson recently completing maintenance at Stirling and GBP 6 billion being invested in the development of the SSN-AUKUS programme.Complementing Pillar I, the first flagship project under Pillar II focuses on uncrewed undersea vehicles aimed at enhancing surveillance, strike capabilities, logistics support and the protection of critical seabed infrastructure. Delivery is expected by 2027.The initiative reinforces AUKUS as a cornerstone of Indo-Pacific security and seeks to ensure that Australia, the United States and the United Kingdom remain leaders in advanced maritime and undersea warfare capabilities.Australia had originally awarded French shipbuilder DCNS, now known as Naval Group, a contract worth AUD 50 billion to build 12 conventionally powered submarines to strengthen its undersea fleet.These were to be the diesel-electric Shortfin Barracuda Block 1A submarines, a larger conventional variant of France’s Barracuda-class nuclear-powered submarine.However, in September 2021, Australia cancelled the Shortfin Barracuda programme following the announcement of AUKUS. The decision triggered a major diplomatic dispute with France, significantly straining bilateral relations. In response, France temporarily recalled its ambassador from Washington, DC, in an unprecedented display of diplomatic displeasure.