In September 2021, Australia, the United Kingdom and the United States formed a trilateral security partnership to enhance deterrence in the Indo-Pacific. Five years later, the pact has progressed amid leadership changes and geopolitical shifts.
AUKUS formed as a response to the growing need to counter security threats in the region, particularly from the Chinese Communist Party and Russia. “The challenges that we faced in the Indo-Pacific region were becoming more substantial and the risks to Australia were rising, in particular relation to the maritime capabilities and submarine capabilities,” said Greg Moriarty, Australia’s ambassador to the U.S. He joined Steven Lovegrove, U.K. prime minister’s special representative on AUKUS, and Kurt Campbell, former U.S. deputy secretary of state, for a September 2026 virtual discussion on AUKUS progress hosted by the Center for Strategic & International Studies. To meet these threats, Moriarty said, Australia needed to upgrade its submarine capabilities from conventionally powered, which are more easily detected.
For the U.K., AUKUS emerged from “a recognition of the fact that our prosperity was very much reliant on freedom of navigation and trade routes … in the Indo-Pacific,” Lovegrove said. “We wanted to make sure that that bit of the world continued to be safe.” AUKUS also provided an avenue to rebuild the submarine industrial base, which had declined since 1990, he said.
The panelists agreed that AUKUS has made progress on its initial goals, but much work remains.
AUKUS consists of two phases, called “pillars.” Pillar 1, considered the centerpiece of the partnership, includes delivery to Australia of a nuclear-powered submarine capability. The move represents the first time the U.S. has shared its sensitive nuclear-propulsion technology with an Ally since the 1958 Mutual Defense Agreement with the U.K.
Pillar 2 calls for the three nations to enhance joint capabilities and interoperability with cutting-edge defense technologies, including cyber, artificial intelligence, quantum, electronic warfare, undersea capabilities and information sharing.
“The Indo-Pacific and the North Atlantic … it is artificial to pretend that they are completely divorced theaters,” Lovegrove said. “We are very conscious of wanting to be able to play a more full and effective role with more boats, better boats in those areas because the threat from the Russians in those waters is very, very acute, and we need to make sure that we maintain our edge.”
AUKUS progress includes several milestones. In July 2026, Rolls-Royce began construction on a new plant in Derby, U.K., to build submarines for Australia and the U.K. In May 2026, the three nations announced they will jointly develop interchangeable payloads and enabling systems for uncrewed undersea vehicles. The Deep Space Advanced Radar Capability project, a network of ground-based radars designed to track small objects in space, is under development in Western Australia. AUKUS nations also are conducting trilateral exercises and testing, including the annual exercise Maritime Big Play and the Hypersonic Flight Test Experimentation project.
As Australia works to enhance its security capabilities, it is developing the workforce needed to support the submarines, Moriarty said. More than 140 Royal Australian Navy personnel have graduated from training and begun working on U.S. submarines, and another 230 people from the Australian Submarine Corp. have received submarine maintenance training at Joint Base Pearl Harbor-Hickam, Hawaii. Australia will host a U.S.-deployed submarine for the first time in 2027. “Our naval personnel have met the maintenance standards that we have been required to meet,” he said. “We are working with the U.S. and the U.K. to make sure that our people — both our civilian maintainers and our naval personnel — can meet those standards.”