Australia and Japan are entering a new era of defense cooperation marked by increased trilateral military engagement with the United States and deepening industrial and strategic alignment. Long bound by shared values, Canberra and Tokyo are leveraging their partnership to bolster deterrence amid an increasingly complex security environment, including growing tensions with China.
Australia’s inaugural participation in Orient Shield in September 2025 underscored the momentum. The Japan-hosted exercise, which included live-fire mortar drills and simulated medical emergencies, brought together 200 Australian Army Soldiers, 1,200 Japan Ground Self-Defense Force (JGSDF) personnel and 700 U.S. military personnel.
The drills are “proof of the nations’ strengthening ties and shared values in the current global climate,” Lt. Gen. Makoto Endo, commander of the JGSDF’s Middle Army, said in a news release. Orient Shield aimed “to test and refine our procedural interoperability while conducting combined operations,” building on command integration from Exercise Yama Sakura, he said.
“Our strong trilateral partnership is an important pillar of regional security, and crucial to collective deterrence in our region,” said Australian Army Brig. Louise Martin, commander of 2nd Health Brigade.
The engagement is part of a strategic convergence between Canberra and Tokyo. The 12th consultations among the nations’ defense and foreign ministers in Tokyo in early September 2025 produced a comprehensive vision for elevating defense cooperation. Key outcomes included expanded operational cooperation under the bilateral Reciprocal Access Agreement (RAA) and joint liaison officer placements, according to a statement. The RAA, signed in January 2022, has enabled more than 40 activities, including Australia’s first participation in Orient Shield and Japan’s increased involvement in Australia-based drills.
Shared concerns over Beijing’s regional posture are fueling increased coordination between Australia and Japan, according to Dan Darling, a defense analyst with U.S.-based Forecast International. “They both are tailoring their militaries for extended-strike capabilities that ideally would enable their militaries to deter aggressors at distance before they reach their respective shorelines,” he told FORUM.
Meanwhile, Australia’s selection of Japan’s upgraded Mogami-class frigate as its next general-purpose warship — announced during the recent ministerial talks —is a landmark in defense industrial cooperation. “It helps Australia increase its naval warship capacity on an expedited timeline and helps provide Japan’s own defense industrial sector a boost,” Darling said.
The nations also are collaborating on dual-use innovations with military and civilian applications. With the United Kingdom and the U.S., they tested advanced capabilities during Exercise Talisman Sabre in Australia in mid-2025, including underwater autonomous systems, according to the joint ministerial statement. The ministers also confirmed plans to expand innovation through joint research in aerospace materials and combat aircraft.
Japan deployed its largest contingent yet to Talisman Sabre, which featured more than 40,000 personnel from 19 nations. Japan, meanwhile, hosted Australian and U.S. forces for air combat drills during Exercise Bushido Guardian at Misawa Air Base in September and October 2025.
The pattern of Australia-Japan engagement highlights a deliberate shift, Darling said. “The two nations have drawn closer together over the past 15 years,” he said. “They both are concerned by Beijing’s push to control — through military presence, coercion or force — the space beyond [the] first island chain.”
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