As artificial intelligence (AI) and robotics technologies progress, the increasing autonomy of unmanned military systems will drive new operational concepts with the potential to transform modern war. The Indo-Pacific’s contested littoral sandboxes and maritime proving grounds will be a decisive test for the future of autonomous warfare at sea. Here, the success of the United States, Australia and like-minded partners in unmanned warfare will depend on sustained, smart and collaborative investments in fundamental research, operational concept development and systems deployment. Yet, just how transformative these systems will be remains unclear owing to significant political and institutional hurdles. In the face of these barriers to changing force structures and phasing out legacy systems, the United States FY2020 defence budget will provide a useful indicator of American intention to move experimental prototypes off the shelf and into production.

China enjoys a home court advantage in the Indo-Pacific’s maritime environment. Autonomous systems, however, offer the United States and its regional allies the potential to address strategic and operational challenges posed by Chinese anti-access capabilities. The United States and Australia have undertaken promising experimentation in unmanned sea warfare beneath, on and above the ocean’s surface. Some projects, like DARPA’s Sea Hunter, have achieved relatively quick success. Other concepts, like an unmanned carrier-launched combat aircraft or GPS-like maritime networks, require further research and development. As the United States and Australia modernise their naval systems, they must realistically assess what future unmanned warfare at sea will look like in terms of threats, operational challenges and new concepts and capability needs. If serious budgetary commitments are made to shift experimental systems to production, US-Australian coordination on technology development and integration can establish the basis for interoperable and collective defence in the Indo-Pacific.