The unusual deployment by three navy ships over the past month has prompted a debate in Australia about its aging fleet and reliance on the United States.

For nearly a month, three Chinese warships made an unannounced journey around Australia, leaving the country on high alert. The flotilla consisted of a cruiser, a frigate, and a replenishment tanker,

Both Australia and New Zealand have another worry, that China may be strengthening its ability to deploy its forces in the region by cosying up to South Pacific microstates. In February the Cook Islands agreed to form a “comprehensive strategic partnership” with China and announced plans for Chinese investment, including port-building.

Beneath the waters off the Western Australian coast, sonar operators aboard a U.S. Navy Virginia-class submarine are adjusting to a new environment. The quiet hum of advanced sonar systems is accompanied by the chatter of dolphins as the submarine navigates unfamiliar territory.

On a training exercise from its home port in Guam, USS Minnesota is a forerunner to four Virginia class submarines that will be hosted at a Western Australian naval base from 2027, under the AUKUS partnership to transfer nuclear submarine capability to Australia.