Defence commentators have devoted much attention in recent years to the development of long-range anti-ship missiles, whether in the form of anti-ship ballistic missiles (ASBMs) or hypersonic cruise missiles. These discussions invariably focus on the concept of anti-access/area denial (A2/AD) and its employment by China, or occasionally Russia or Iran, against the US Navy. Some observers have gone on to question whether such technologies render high-value surface warships defunct ^[1].

These debates are important and interesting but have tended to miss larger questions about how the new technologies may have altered the relative balance of power between land and sea, and what impact this has on maritime strategy in general.

One notable exception to this has been James Holmes’s rehabilitation of the concept of a fortress fleet to describe the relationship between the People’s Liberation Army Navy and the new Chinese anti-ship missiles. ‘Fortress fleet’ was a term coined by the great maritime strategist Alfred Thayer Mahan to describe the activities of the Russian fleet during the Russo-Japanese War. He deplored the way the Russians tied their fleet to fortified harbours, rarely venturing out from under the protection of coastal artillery.

But times have changed. Holmes has regularly argued ^[2] that ‘the day of the fortress fleet has come, courtesy of extended-range, precision, guided-missile technology’. In certain ways, it’s difficult to disagree. Developments in range and firepower mean that any fleet operating under the ‘guns’ of such a modern-day fortress will possess a profound advantage.

Mahan’s criticism of Russian actions was not, however, based on the limited range of the artillery at Port Arthur. In fact, he was far more measured in his critique of coastal fortifications than is generally acknowledged, carefully noting that ^[3] you must ‘give each element—coast fortress and fleet—its due weight, its due consideration, in the scheme of military and naval policy’.

Mahan’s attack on fortress fleets was about mentality, not materiel. As he saw it, the concept of a fortress fleet stood for ‘defensive ideas’ stemming from an ‘inadequate conception’ of the purpose of a fleet. This was a policy adopted by a continental power which saw sea power solely in terms of the protection of its territory from potential rivals. In this respect, Mahan would fully understand, if not condone, the contemporary focus on A2/AD concepts developed in the face of US naval power.

China, Russia and Iran do not, however, have a monopoly on seeking to use the land to control the sea. Recent developments in the US, most notably in the shifting focus of the Marine Corps ^[4], make it very apparent that land-based weaponry is going to be a crucial tool in the arsenal of those seeking sea control as well as sea denial. The concept of a fortress fleet can certainly apply to Russia, and perhaps China, but it makes very little sense in the context of a nation looking to exert command of the sea (or oceanic sea control).

This brings us back to the question of where this new breed of long-range anti-ship missiles fits within maritime strategy. Here it’s worth turning to the other titan of maritime strategy, Julian Corbett. Corbett famously had a subtly different concept of command of the sea than Mahan, particularly in terms of the vessels that would exercise that command.

Mahan had always emphasised the role of battlefleets, whereas Corbett argued that ‘for the actual and direct control of either commercial or military lines of passage and communication battle fleets are unnecessary and unsuitable’. Instead, Corbett believed the role of the battlefleet was to provide a security umbrella, preventing the enemy from interfering with the exercise of command of the sea by cruisers and flotilla craft.

As a historian, Corbett was careful to emphasise that these broad roles within the theory of naval warfare were not tied to specific materiel. Over the century since his death, the job of providing that security umbrella has passed from the battlefleet to aircraft carriers and, in certain circumstances, land-based aviation.

Long-range anti-ship missiles seem likely to be an addition to the suite of tools used to carry out this traditional role of naval warfare. These weapons, like Corbett’s battlefleet, appear to be ill-suited to the role of exercising command of the sea, but that doesn’t mean they necessarily strengthen sea denial over sea control, or make surface vessels redundant.

Instead, in the same way that the British Grand Fleet provided the security for the destroyers and minesweepers to exercise command during the World War I, so these weapons can fit into a wider view of how modern navies facilitate the use of the seas.

In many respects, anti-ship missiles fit easily into this Corbettian view of naval warfare. However, there are some major differences which seem likely to have a profound impact on maritime strategy. The first is that the traditional materiel used to provide the umbrella of security has always been seaborne, and therefore benefits from the principle of the interconnectedness of the oceans.

The 19th century Royal Navy ruled the waves the world over, despite rarely sending battlefleets out of European waters. The mere fact that it could was sufficient. Land-based weapons naturally lack this flexibility.

The second difference is one of cost. High-end anti-ship missiles themselves are extremely expensive, and the targeting systems and other infrastructure that they require are probably even more costly. However, it seems certain that such costs will still be far lower than the price of the traditional arbiters of sea control ^[5]. This potentially places them within reach of countries that would otherwise have been unable to afford to challenge for command of the sea.

The growth of anti-ship missiles as a provider of Corbett’s security umbrella offers the prospect not merely of increased sea denial and A2/AD, but also of the growth of regional powers able to exercise meaningful command of the sea across broad swaths of the oceans that they border.

It should be added that these weapons have considerable vulnerabilities, not least in the infrastructure and ‘kill chains’ that enable them to successfully hit a target. Also, despite the continual discussion of the death of the aircraft carrier, it’s far from certain that they will end up having greater capability, or survivability, than existing platforms. Instead, it seems likely that they will offer a different form of capability, one that might be available to more nations, or one that can be deployed in an environment that would be too risky for traditional platforms.

The development of these new technologies will unquestionably affect naval warfare in ways that are difficult for us to assess. Corbett and Mahan can’t provide us with any answers to these questions, but they do help tease out what is consistent within naval warfare from what is ephemeral. From this perspective, it appears that the impact of long-range land-based anti-ship missiles may be both more subtle and more profound than the recent focus on sea denial and A2/AD suggests.