AUKUS partnership marks 5 years with milestones

Sentry

In September 2021, Australia, the United Kingdom and the United States formed a security partnership to enhance deterrence in the Indo-Pacific. Five years later, the trilateral pact has progressed amid geopolitical shifts.

AUKUS formed in response to the growing need to counter security threats in the region, particularly from China 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,” Greg Moriarty, Australia’s ambassador to the U.S., said during a September 2026 discussion hosted by the U.S.-based Center for Strategic and International Studies (CSIS). To meet those threats, Moriarty said, Australia needed to upgrade its submarine capabilities from a conventionally powered to a nuclear-powered fleet.

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,” Steven Lovegrove, the U.K. prime minister’s special representative on AUKUS, said during the CSIS event. “We wanted to make sure that that bit of the world continued to be safe.”

AUKUS also provided an avenue to rebuild the U.K.’s submarine industrial base, he said.

AUKUS Pillar 1 includes delivery to Australia of a nuclear-powered submarine capability. Pillar 2 calls for enhancing joint capabilities and interoperability with defense technologies including cyber, quantum, electronic warfare and undersea capabilities.

“The Indo-Pacific and the North Atlantic … it is artificial to pretend that they are completely divorced theaters,” Lovegrove said.

In May 2026, the AUKUS partners announced they will jointly develop interchangeable payloads and enabling systems for uncrewed undersea vehicles. Meanwhile, the Deep Space Advanced Radar Capability project will establish a network of ground-based radars designed to track small objects in space, with sites in each nation. AUKUS nations also are conducting trilateral exercises and testing, including with hypersonic technology.

Australia is developing the workforce needed to support nuclear-powered submarines, Moriarty said. More than 140 Royal Australian Navy personnel have graduated from training and begun working on U.S. submarines, while 230 personnel from the Australian Submarine Corp. have received submarine maintenance training at Joint Base Pearl Harbor-Hickam in Hawaii.

“Our naval personnel have met the maintenance standards that we have been required to meet,” Moriarty 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.”

Sentry is a professional military magazine published by U.S. Strategic Command to provide a forum for national security personnel.