Overview: There’s a possibility that Australia’s future submarine (FSM) will be based on a Japanese design. The government has explicitly kept that option open, along with the possibility of buying the boats from Germany or France.

Wherever the FSM is designed, built, or both, the supplier’s political reliability and technological suitability are vital, as is establishing trust in the ability of both sides to work together effectively and efficiently on such a complex capability.

This paper examines what a possible Australian–Japanese submarine deal would mean for the wider relationship between the two countries, as well as the geostrategic implications.