Japanese Prime Minister faces submarine leasing push for Australia
An ASPI report released today says Australia should consider leasing Japanese submarines as a backup for the AUKUS submarine plan. The recommendation comes as japanese prime minister Sanae Takaichi visits this week, putting the option on the agenda while Australia weighs risks across its submarine program.
Sanae Takaichi visit agenda
Prime Minister Sanae Takaichi is the key named figure in the report’s timing. The report says the topic should be raised during her visit this week, when Australia and Japan are already working through agreements on energy, defence and critical minerals.
The proposal is narrow in scope. It does not replace AUKUS. It argues for a Japanese option to cover a submarine capability gap if Australia’s current plan slips.
Australia’s submarine gap risk
The report points to three pressure points: the extension of the operating life of Australia’s current fleet of six Collins-class submarines, the ability of the United States to ensure the timely delivery of between three and five Virginia-class submarines, and the construction of the SSN-AUKUS in Australia for delivery to the Royal Australian Navy from 2040 onwards.
Together, those risks could deprive Australia of a modern, sovereign submarine capability for more than a decade. The gap could appear as early as 2030 and last into the 2040s.
That possibility is awkward for Canberra because Australia spent more than a decade trying to replace its Collins-class submarines with a similar capability, and that effort proved unsuccessful, costly and politically bruising. The report says Australia has no appetite to start a full acquisition process for a new class of conventional submarines if a gap opens.
Japanese submarines and the next US step
The report argues leasing a modern submarine capability would present far fewer challenges than buying one outright. It says leasing or otherwise rapidly acquiring Japanese submarines would require few resources, at least initially, and would not detract from the Optimal Pathway until that path became obviously unachievable or significantly delayed.
Japan is unlikely to join the submarine component of the AUKUS defence partnership between Australia, Britain and the United States, which is why the report treats a Japanese lease as a risk-management option rather than an alliance shift. The next US administration is likely to provide certification to US Congress in 2030 or 2031, a point that sits inside the same window in which the capability gap could first open.
For Australia, the practical issue is not whether AUKUS exists, but whether the country can keep a modern submarine capability in service if the Collins-class, Virginia-class and SSN-AUKUS schedules all move at the slow end of their ranges. That is the choice the report wants Australian ministers to weigh while Sanae Takaichi is in the country this week.
