Australia will receive used U.S. nuclear-powered submarines as part of an amended defense agreement announced at the 2026 [1] Shangri-La Dialogue in Singapore.

The move accelerates the AUKUS partnership's goal to shift maritime power in the Indo-Pacific. By integrating used nuclear vessels and new drone technology, the three nations aim to secure critical seabed infrastructure and increase surveillance capabilities.

Under the "Pillar Two" subsea security pact, the United States, United Kingdom, and Australia will jointly develop advanced uncrewed undersea vehicles (UUVs) [2]. These underwater drones are designed to protect energy pipelines, and communication cables from interference or sabotage [3].

Australian Defence Minister Richard Marles represented the nation at the Singapore summit where the updated terms were finalized. The shift to used submarines allows for a faster transfer of capabilities than building new vessels from scratch. These submarines are expected to arrive in Australia by 2027 [2].

The agreement emphasizes a deepening of maritime cooperation among the three partners to enhance strike capabilities across the region [3]. The deployment of these assets will focus on maintaining stability and protecting the flow of global trade through Indo-Pacific waters.

The development of UUVs represents a significant leap in autonomous warfare. These systems will work alongside the manned nuclear submarines to create a layered defense network across the ocean floor [2].

“Australia will receive used U.S. nuclear-powered submarines”

The decision to provide used submarines instead of exclusively new builds suggests a strategic urgency to bolster Australian naval capabilities before 2027. By pairing these vessels with autonomous underwater drones, AUKUS is transitioning from a traditional fleet-based deterrent to a hybrid surveillance network capable of monitoring the deep-sea infrastructure that sustains global internet and energy markets.