AUKUS nuclear submarine sale under scrutiny as Trump tariffs rattle Australia

PERTH - The sale of nuclear-powered submarines to Australia under the AUKUS treaty faces new doubts as U.S. President Donald Trumps tariffs take hold, and amid concern in Washington that providing the subs to Canberra may reduce deterrence to China.

Whether the United States can boost submarine production to meet U.S. Navy targets is key to whether Australia can buy three Virginia-class submarines starting in 2032, Defence Minister Richard Marles said last month, after talks with his U.S. counterpart, Pete Hegseth.

Australia faces a previously unreported 2025 deadline to pay the United States $2 billion to assist with improving its submarine shipyards. The Trump administration has asked for more funding, Marles said in March.

Consternation is growing in Washington that Australias reluctance to even discuss using the attack submarines against China means that transferring them out of the U.S. fleet to Australia would hurt deterrence efforts in the Indo Pacific, according to experts and documents.

If you want to deter conflict, in peacetime you need to talk about using it in wartime and we haven’t seen a willingness yet on the part of the Australians, government or officials, to make that kind of threat, said former U.S. Navy strategist Bryan Clark, director of the Center for Defense Concepts and Technology at the Hudson Institute, who is advising the Australian Defence Force on force design.

In a previously unreported recent multilateral war game simulating a response by U.S. allies to a Chinese blockade of Taiwan, Australian Defence Force commanders did not use nuclear-powered submarines in the South China Sea to attack Chinese targets, instead focusing on protecting Australias northern approaches with airpower, drones and missiles, said Clark, who ran the exercise.

The distance from China made an airpower and surface fleet approach less risky, and the submarines were instead placed in