The AUKUS Submarine from an Australian Strategic Viewpoint

The AUKUS Submarine from an Australian Strategic Viewpoint

By Josh Phillips

In September 2021, Australia cancelled a $66 billion deal with the government of France to acquire a dozen new ‘Shortfin Barracuda’ diesel-electric submarines and, instead, finalized a replacement within the agreement known as the Australia, United Kingdom, United States pact – the AUKUS agreement. In this deal, the U.S. and the U.K. are to build and deliver eight new Virginia-class nuclear-powered subs to the Royal Australian Navy. This has many implications, but one factor in Australia’s decision to acquire nuclear submarines is their superior range, and the Lombok Strait in Indonesia is one area in which this range matters. Lombok is the only strait between the Indian and Pacific Oceans that is deep enough for submarine transit, and is a narrow strait that future RAN nuclear submarines would be able to monitor more effectively. Australia acquiring nuclear subs could allow RAN to project naval power in a more sustainable fashion.

Nuclear submarines are an asset that increases in value over time.  They are powered by reactors that do not need to be refueled for decades. They possess a substantial range, have quieter engines, and can remain submerged for up to three months. Diesel submarines do not offer the same longevity. If launched from Australia’s primary submarine base in Perth, it would take a deployment of diesel-powered Shortfin Barracudas around three to four days to reach the Lombok Strait at top speed, only giving the force a maximum of two weeks of effective patrol time before needing to surface. If Lombok is to be an area of interest for the RAN, then longer deployments are needed, and nuclear submarines offer operational superiority. Australia, given its national security objectives and the state of the Indo-Pacific, can most certainly fulfill more strategic aims with nuclear-powered Virginia-class submarines.

Additionally, Australia is currently upgrading their northernmost submarine facility, the HMAS Coonawarra base in Darwin, which could extend RAN’s northern reach even further. The base is currently undergoing a four-year, $200-million refit and capability enhancement. This port investment certainly gains greater importance in light of AUKUS, as the location of this facility would serve nuclear submarine range.  Yet, having the ability to launch these future RAN nuclear submarines from a location so close to Lombok would ease the scale of deployment and better positioning RAN forces overall.

Australia’s desire to extend their Indo-Pacific reach is clear. In their 2020 Defense Strategic Update, the Australian government decided that defense planning will almost solely focus on regions ranging from the north-eastern Indian Ocean, through maritime and mainland South East Asia to Papua New Guinea and the South West Pacific. Among the long-standing priorities in Australia’s defense strategy are denying the use of the sea to a potential adversary. Scott Morrison, former Prime Minister of Australia, cited growing security challenges in the region as one of the drivers of the new AUKUS partnership. Euan Graham of the International Institute for Strategic Studies says the submarine switch “underlines the seismic change to Australia’s security environment” that has occurred since the submarine contract was agreed with France in 2016. While still somewhat unlikely, the prospect of high-intensity military conflict in the Indo-Pacific is less remote than at the time of the 2016 Defence White Paper, which Australia has noted repeatedly in their 2020 Defense Strategic Update.

Given Australia’s interest in the overlapping areas of the Indian and Pacific Oceans, the monitoring of Lombok is a likely priority for RAN. At its narrowest point, Lombok is only 12 miles wide, providing Australia a variety of naval options for its assets to sustain their monitoring. In the case of heightened regional tensions, Australia could use its nuclear submarines for sea denial and even deploy submarines further than its near seas.

It’s clear that alongside other purposes, an Australian nuclear submarine force will serve as a robust projection of power in the waters around Australia and possibly beyond. Australia would have the potential ability to deploy submarines from the upgraded base in Darwin. This would provide Australia an unprecedented ability to patrol northern waters for extended lengths of time, much longer than a fleet of Shortfin Barracudas would facilitate. The AUKUS deal provides a nuclear-fueled submarine fleet to Australia that serves both its interests and that of Australia’s allies and partners. The uses of this submarine fleet are many, but a look to the Lombok Strait reveals one logical focal point for RAN nuclear submarines.