As China’s massive military build-up drives rising regional security anxieties, Australia is contributing to a more favourable balance of power through AUKUS. This technology-sharing agreement with the United Kingdom and the United States will see eight nuclear-powered submarines (SSNs) in Australian service by the 2050s.

SSNs are overwhelmingly in Australia’s interest because they strengthen the country’s ability to deter war by threatening painful consequences for aggression against Australia, its partners, and its interests. The 2023 Defence Strategic Review explicitly tasks the Australian Defence Force with a deterrence role against a significant military power — a relatively new mission. SSNs are optimal deterrence machines, able to accomplish the essential tasks laid out in the review.

Key findings

• Nuclear-powered submarines (SSNs) will be central to Australia’s defence strategy in contingencies prioritised by the Defence Strategic Review, such as defeating threats of invasion or stand-off attack, countering a naval blockade, and supporting the regional balance of power.
• SSNs will give Australia added strategic weight to deter a more powerful adversary by demonstrating the country’s capability to target forces that would otherwise outrange its own, and which could be used to coerce Australia at a distance.
• To further grow Australia’s deterrent, future governments should consider building more SSNs continuously from the 2050s.