The Royal Australian Navy (RAN) and the United States Navy trained together in the South China Sea in mid-September 2025 in support of a Free and Open Indo-Pacific.
Participating ships included the RAN frigate HMAS Ballarat and the U.S. Navy guided-missile destroyer USS Dewey. Over two days, the navies conducted communications and simulated fires drills, plus information sharing and a combined transit of the sea, a vital global trade route.
“It was a fantastic opportunity to work alongside Ballarat and our Australian allies,” said U.S. Navy Cmdr. Ivan Dobrev, the Dewey’s commanding officer. “Deepening our interoperability with our Allies and Partners here in the Indo-Pacific is the key to enhancing our collective deterrence against any adversary threatening peace and stability in the region.”
The U.S. Navy regularly trains alongside Allies and Partners in the Indo-Pacific to demonstrate a shared commitment to upholding international law. Engagements enable forces to enhance tactical interoperability. The Australian Defence Force also routinely operates in the region.
“This activity is an important demonstration of the resolve that Australia has to supporting an open, stable, and prosperous Indo-Pacific, where international law is respected,” said RAN Cmdr. Dean Uren, commanding officer of the Ballarat.
China makes sweeping claims of sovereignty over the South China Sea and its oil and gas resources despite overlapping claims from Brunei, Indonesia, Malaysia, the Philippines and Vietnam. An international tribunal ruled in 2016 — in a case brought by the Philippines — that China has no legal basis for its sovereignty assertions. China ignores the ruling and uses bullying tactics in its attempt to coerce other claimant states.
The exercise was part of the Ballarat’s regional deployment, which protects Australia’s security and prosperity by enhancing cooperation, and developing capabilities and interoperability, the Australian Defence Department said. A Royal Australian Air Force P-8A Poseidon maritime patrol aircraft supported the transit.
“Australia has a long history of operating in the South China Sea both unilaterally as well as in conjunction with allies and partners,” said RAN Vice Adm. Justin Jones, chief of joint operations. “Operating alongside regional partners enhances interoperability and readiness to respond to shared security challenges.”