At an ASPI conference a few years ago, I remarked that I thought that major surface combatants had been obsolete for many decades, and that the only reason we hadn’t noticed was that there hadn’t been a major naval conflict since World War II. Needless to say, that view wasn’t unanimously subscribed to by an audience that included many senior naval officers.

There was a bit of theatre in the way I chose to phrase the proposition. As I wrote a while back ^[1], all capabilities and platforms have military utility in some circumstances, and the argument should really be about whether the cost of acquiring and sustaining a capability is commensurate with the benefits that accrue from having it. Of course, the persistence, reach and firepower of surface combatants have utility and, at the very least, an adversary will be required to make a considerable effort—and may incur significant losses—to neutralise them.

But my instinct remains that surface fleets would face mortal peril in peer-on-peer conflict, especially when within range of enemy sensors, missile systems or aircraft. The disadvantages of surface vessels are easy to list: they are large and slow, their major defensive systems can’t be reloaded at sea, and they are confined to manoeuvring in two dimensions. Conversely, the threats they face are small, fast, numerous and able to manoeuvre in three dimensions.

Of course, it isn’t a one-way fight, and surface combatants can defend themselves with varying degrees of effectiveness against the various threats likely to come their way. But if there are enough incoming threats, even highly reliable defensive systems will eventually let one through, or run out of ammunition. Sam Goldsmith’s recent Strategist post on the undersized magazines being built into Australia’s future frigates ^[2] is right in its basic idea that more is better where defensive shots are concerned.

There are other possible approaches to survivability in the face of a competent adversary with enough weaponry to sustain an attack. One might try to interdict the ‘kill chain’ further upstream, perhaps by disrupting the adversary’s C4ISR (command, control, communications, computers, intelligence, surveillance and reconnaissance) systems enough to prevent vessels from being targeted in the first place. Or ships could stand off beyond the offensive systems’ reach and try to deliver effects from a safe distance.

But sometimes you’ll want to control the sea to use it for your own purposes, and it won’t generally be possible to do that from afar. Many of Australia’s military strategies involve sea control, and national capability shortfalls such as a lack of a strategic fuel reserve render us vulnerable to maritime interdiction. We need to be able to use the sea, and our current approach seems to be based on an assumption that a dozen or so frigates will enable that. Two books I read recently have helped clarify my thinking about the future of surface combatants. Each of them illustrates the unique advantages that use of the sea can provide, and they both illustrate the costs that can accrue.

In Operation Pedestal ^[3], historian Max Hastings tells the harrowing story of a powerful Royal Navy taskforce, including fast merchant ships, assembled to resupply the beleaguered island of Malta in August 1942. The fleet had to run the gauntlet of Axis aircraft and submarines half the length of the Mediterranean. The sinking by the Japanese of two of the Royal Navy’s major surface combatants in the South China Sea in December the previous year was a rude awakening that demonstrated the necessity for organic air defence for maritime operations within range of enemy land-based aircraft. The Pedestal convoy was therefore provided with substantial defensive resources, including three aircraft carriers (with a fourth attached to a support force). Even so, heavy losses were expected.

The Pedestal fleet’s carrier aircraft and anti-aircraft batteries managed to beat off many air attacks, but enough got through to wreak havoc on the convoy. The damage was exacerbated by torpedo attacks from submarines and fast small boats. In all, the attackers managed to sink an aircraft carrier and ‘mission kill’ another. They also sank two light cruisers, a destroyer and nine of the 14 merchant vessels. Five other vessels were damaged, some beyond repair. That was all achieved for the loss of around 50 aircraft and two submarines.

Importantly, one of the five merchant vessels to arrive in Malta was a tanker, which provided enough fuel to continue air and sea operations for several months. (The story of the survival of the tanker, SS Ohio, is an extraordinary tale of luck, bravery and seamanship, well told by Hastings.) Strategically, the mission might be counted a success, since it kept Malta in the war, allowing aircraft based there to be a continuing menace to the resupply of German forces in North Africa. And only ships could have delivered the quantity of supplies required, which continues to be the case today. But the cost was high, and a repeat, should it have been required, would have been practically impossible.

Similarly, convoys sailed from the UK, US and Iceland to deliver materiel to the Soviets from 1941 to 1945. Losses were sometimes very high—convoy PQ17, for example, lost 24 of 35 merchant vessels a month before Pedestal. Overall, 16 warships and 85 merchant vessels were sunk, but the alliance-management and military benefits of the vehicles, ordnance and aircraft delivered by sea offset those substantial losses.

Sealift was also required to move the men and materiel needed for the American ‘island hopping’ campaign in the Pacific War, as detailed by Ian Toll in the final book of his Pacific War trilogy, Twilight of the gods ^[4]. By 1945 the US had an overwhelming superiority in numbers of ships and aircraft, and Japan was by then a non-peer competitor against vast American resources. But Japanese forces still managed to inflict serious losses on the American fleet during the invasion of Okinawa through kamikaze attacks, in which pilots deliberately flew their aircraft into ships. In that first concerted use of (man) guided weapons, more than 400 vessels were struck. Some were sunk and many others were forced out of the fight by the damage inflicted. But the sheer size of the American fleet allowed it to absorb the losses and prevail—the US Navy had well over 100 fleet and escort aircraft carriers alone in 1945, and around 1,000 combatant vessels in total.

The most significant maritime conflict since World War II is probably the Falklands War of 1982, in which Argentina came close to defeating a Royal Navy taskforce, sinking four surface combatants and several other vessels. When I’ve discussed that conflict with supporters of surface combatants, they sometimes argue that it wasn’t a true test of sea power because the British defences had been allowed to fall well behind the state of the art—to which I point out that at least some of the British systems were recent and highly capable, and the fleet had its own fighter defence in the form of Sea Harriers. And it’s not like the attackers were top shelf—the Argentine forces had a single-digit number of Exocet guided weapons available, but then managed multiple hits on vessels with ‘dumb’ gravity bombs after the Exocets ran out.

Obviously, we don’t have contemporary data. But the historical data bears out the perils of ships in the face of concerted attacks. And I think the trends since then have all gone the wrong way for surface vessels. The ships of the 1940s had defensive capabilities with much deeper magazines than today’s vessels (such as our future Hunter-class frigates with just 32 missile cells), allowing them to defend themselves in contested waters for longer.

Military fleets today are much smaller than their predecessors, so losing even a handful of major units could be a crippling blow. And the decline of national shipping fleets in Australia and allied countries means that we can’t press civilian merchant vessels into service as was done in World War II, though the federal opposition recently announced a policy ^[5] to stand up a small Australian-flagged fleet. Finally—and possibly most importantly—the calculus of relative size, speed and manoeuvrability remains highly unfavourable.

The rational—and historically observed ^[6]—response to increased lethality on the battlefield is an increased dispersion of forces. Instead, we’re responding to a more lethal maritime environment by building smaller numbers of increasingly expensive and irreplaceable (at least on the likely timescale of conflict) vessels, with a greater proportion of their payload devoted to self-defence.

As the historical examples show, it’s sometimes vital to be able to use the sea, at least for limited times at critical junctures. As an island continent, our military options will be limited if we can’t do that, and we also could face critical supply problems. We should be thinking about how to manage those issues in a future in which our prize assets could struggle badly. I’m pretty sure that putting our increasingly vulnerable eggs into fewer baskets isn’t the right approach.