Australia’s decision to spend $50 billion on 12 French diesel-electric Shortfin Barracuda submarines reflects a long-established government preference for non-nuclear submarine forces. But will this preference remain strategically credible in future years if our strategic circumstances continue to deteriorate and if potential competitors continue to expand and to modernize their submarine fleets?

Australia’s new submarines are a conventional variant of a French nuclear-powered submarine design, and are scheduled to enter service from the early 2030s to the 2050s. So perhaps we need to remain open to possibly acquiring some nuclear-powered Shortfin Barracudas during the lengthy building period. A mix of conventional and nuclear submarines might prove to be an optimum outcome for Australia.

Of course it would be necessary to consider serious questions including cost, capability, crew training and availability, submarine numbers, local access to nuclear technology and nuclear technicians, inter-service rivalries, and domestic political acceptability among other things. But if changing circumstances were to force a decision on government, there’s at least some intriguing fairly recent history to help guide decision-makers.

The history is detailed in the prize-winning The Silent Deep by Peter Hennessy and James Jinks (Penguin Books, 2016), a history of the British Royal Navy submarine service since 1945. Hennessy and Jinks reveal the impact on the Royal Navy of the October 1957 visit to the UK of the USS Nautilus, the world’s first operational nuclear submarine, to take part in Operation Rum Tub, an exercise that matched Nautilus against Royal Navy ships.

In the exercise, Nautilus tore the Royal Navy apart so comprehensively that Lord Louis Mountbatten, the First Sea Lord, was moved to write at the time ‘we now appreciate that we are in the presence of a revolution in naval warfare in some ways more far-reaching than the transition from sail to steam’.

The Commander in Chief Home Fleet, Admiral Sir John Eccles, summed up the four key advantages of the nuclear submarine. It had complete freedom of action in three dimensions, it could disregard threats from the air because it could stay submerged, it had a good picture of what was happening on the surface, and it was ‘vastly superior’ to surface ships and conventional submarines in the attack role.

The Admiralty Board declared: ‘If the Royal Navy did not acquire these submarines it would cease to count as a naval force in world affairs’. It’s worth underscoring that these judgements on nuclear submarines were written 60 years ago.

Hennessy and Jinks detail the saga of Britain’s initial acquisition of four nuclear submarines with what passed for assistance from American Admiral Hyman G. Rickover. They show how the acquisitions transformed Britain’s ability to deliver nuclear weapons from the sea rather than from the air. It’s a remarkable narrative of Cold War strategic evolution.

Given the changing and increasingly fraught strategic environment facing Australia, defense planners cannot sit back contentedly as the new submarine construction gets underway. It may be that conventional submarine technology today is far superior to what was available to the Royal Navy during Operation Rum Tub in 1957. But it is also certain that nuclear submarine technology has advanced since the era of USS Nautilus. Australia needs to remain nimble and flexible in its force structure judgements

A fleet of conventional Shortfin Barracuda submarines would doubtless contribute to Australia’s ability to deter potential foreign intrusions and to support international naval coalitions with allies like the United States and Japan. But Australians would do well to recognize that in regional terms it is a very small fleet indeed.

North Korea, for example, has the region’s biggest submarine fleet with some 70 decrepit old tubs. China has some 68 submarines including around 10 nuclear submarines and it is working ferociously to increase and modernize its fleet. Indonesia has two submarines in service, two under sea trials and one under construction and it’s moving to update and modernize.

Of course these sketchy and imprecise raw numbers mean little. What matters is the quality of the boats and the lethality of their arms. Happily Australia’s key ally, the United States, has far and away the most powerful submarine fleet globally with some 66 boats, all nuclear-powered. What is much less clear is whether the US will remain a fully engaged partner in the Trump and post-Trump eras.

Which is why there may be some sense in noting the lessons of history. Back in 1957, as Hennessy and Jinks argue, the question was not whether the UK could afford nuclear submarines. After Nautilus, the question was whether the UK could afford to be without them. That question might, in time, confront Australia.

This first appeared in ASPI’s The Strategist here.

Image Credit: Reuters.