Asymmetric naval warfare
Lessons from the Mediterranean in the Second World War
The use of asymmetric naval warfare is most often linked with small(er) navies facing numerically, and often qualitatively, superior adversaries. While perfectly logical, this association fails to account for the utility of asymmetric tactics, strategies and technologies in a number of different scenarios, including where a globally superior, but overstretched, force must deal with a locally superior and concentrated one.
Since the beginning of Russia’s full-scale invasion of Ukraine in 2022, the Black Sea has provided an excellent case study on how vulnerable a large navy can be to asymmetric methods, such as those employed by Ukraine. Kyiv’s use of aerial and surface drones, minefields and anti-ship missiles, combined with ever-evolving unconventional tactics, has repeatedly taken the Russian Black Sea Fleet by surprise and nullified its superiority, essentially pushing it to retreat into a defensive posture.
Forced by circumstance in the early stages of the conflict, Ukraine has had to invest financial and human resources into the development of asymmetric tactics and the acquisition of related technologies in order to exercise some level of sea denial against the Russian Navy. Ukraine’s success provides a useful blueprint for other militaries facing similarly unfavourable odds, but it should also come as a reminder that asymmetric warfare, and the resulting capabilities, can – and should – be embraced by much more capable navies.
The struggle for the Mediterranean
The Mediterranean theatre of the Second World War, involving the Royal Navy and the Italian Regia Marina between 1940 and 1943, illustrates how more evenly matched forces can mutually deny each other’s freedom of action in the early stages of a conflict, as well as how they can fail to incapacitate their opponent significantly even after dealing serious blows, as in the later stages of the war, following a number of British victories.
At the outbreak of the war, Italy was a regional naval power, concentrating most of its forces and assets in and around the Mediterranean. By contrast, the British Empire was an outstretched global naval power, with a Mediterranean Fleet roughly matching its Italian adversary in numbers and firepower.
In the 1930s, the Regia Marina had begun thinking about developing vehicles specially designed for penetrating enemy port defences – including human torpedoes – to complement its existing fleet of torpedo-armed motorboats, or Motoscafo Armato Silurante (MAS). Despite some scepticism among naval leadership, as the war approached, the 1st MAS Flotilla (and later its offshoot, the 10th Flotilla) focused its efforts on developing and improving explosive motorboat designs, alongside human torpedoes – Siluro Lenta Corsa (SLC) – and the appropriate delivery systems, as well as the divers’ underwater breathing apparatus.
The SLC in particular offers an interesting example of how innovation is not necessarily about making rapid technological advancements, but can often be unleashed simply by using existing technology and reimagining its applications. Indeed, the first 11 units of the initial series of SLC were built from existing torpedo parts. This type of functional innovation, as opposed to purely technological, is especially useful in asymmetric operations.
Despite the first attempts to enter British ports failing due to technical issues with the still-rudimentary SLCs, the 10th Flotilla eventually managed to inflict serious damage on the Royal Navy in the wake of the humiliation at the Battle of Taranto, where, on the night of 11th November 1940, HMS Illustrious launched 21 Swordfish torpedo bombers and surprised the Italian fleet while it was in port.
Although the opposing surface fleets were well matched numerically, the Regia Marina was increasingly vulnerable to the Royal Navy’s use of radar; in which Italy had hitherto invested few resources, deeming it of secondary importance amid other priorities. Asymmetric capabilities, such as those being refined by the 10th Flotilla, were therefore becoming a lifeline of sorts – as would soon become evident.
On the north coast of Crete, in the early hours of 24th March 1941, six Italian explosive motorboats, commanded by Lt. Luigi Faggioni, entered Souda Bay, where a Royal Navy force composed of cruisers, destroyers and a dozen merchant ships were at anchor. The Italian motorboats managed to pierce through the British defences, hitting and incapacitating HMS York, a heavy cruiser, and sinking a Norwegian tanker.
Yet, only days later, the Italian surface fleet suffered a heavy blow off Cape Matapan in the Aegean Sea, losing three heavy cruisers and two destroyers. However, this new humiliation suffered by the Regia Marina, facilitated to a degree by British code-breaking and radar technology, did not put its fleet out of action. The battle for the Mediterranean continued to rage until the Armistice of Cassibile was signed in September 1943.
On 19th December 1941, the Italians were able to deal another huge blow with the raid on Alexandria, where six Italian frogmen, equipped with three human torpedoes, disabled two British battleships (HMS Valiant and HMS Queen Elizabeth). This came at a particularly challenging time for the Mediterranean Fleet, after a series of setbacks and the redeployment of a number of Royal Navy warships to the Pacific to face the Imperial Japanese Navy.
The story of the 10th Flotilla and its actions against the Royal Navy offer a valuable example of how even a large, modern and capable force such as the Regia Marina, which in fact began the Second World War with a slight numerical advantage over the Mediterranean Fleet, ended up relying on asymmetric and unconventional methods to achieve some of its greatest victories in the war.
Italy had invested large quantities of resources in its surface and submarine fleets throughout the 1930s, and there was a degree of confidence in its ability to disrupt the outstretched British and French fleets while concentrating the Regia Marina’s efforts in the Mediterranean. Reality quickly proved the challenge was greater than anticipated, and the limited investment initially spared for developing and acquiring the 10th Flotilla’s capabilities led to an absolutely essential, and highly cost-effective, tool.
Lessons for advanced navies
Looking at NATO’s military capabilities today, and drawing lessons from the struggle for the Mediterranean in the early 1940s, as well as from Ukraine’s denial of a vastly numerically superior Russian Black Sea Fleet, it may be useful to warn against a complacent approach to capability planning. While it is true that NATO navies are in many ways still technologically superior to their Russian and Chinese counterparts, this should not prevent planners from pursuing unconventional, asymmetric capabilities at scale. Asymmetry in warfare should not be seen as a one-way street.
The highly asymmetric naval engagements of the conflict in Ukraine show first and foremost that NATO navies should be prepared to defend against asymmetric threats. The Russian fleet may indeed suffer from widespread negligence, but its demise in the Black Sea should be ascribed largely to Ukraine’s ingenuity and ability to adapt. These engagements should also serve as a reminder that superior numbers, firepower and technology can be denied, or at least blunted, if fleets are prevented from leaving port altogether; even more so if they are crippled by unconventional means while supposedly safe in their bases.
Such was the lesson inflicted by Italian pioneers against the technologically and operationally superior British Mediterranean Fleet. Conversely, the navies of free and open nations have the opportunity to start developing new approaches to disrupting potential adversaries in unconventional ways. This comes at a time when there is still an appreciable technological edge – especially with regards to Russia.
With this goal in mind, NATO navies should replicate (and adapt to fit their circumstances) Kyiv’s pioneering use of different types of aerial and surface drones against Russian ships, air defences and infrastructure. As most NATO, and especially European, navies struggle to increase hull numbers and seek to bolster the firepower of their surface combatants, there is a risk that not enough attention is being given by larger and more conventionally capable navies to instruments and methods more suitable in asymmetric contexts.
Should an adversary be able to hinder NATO naval operations significantly through the competent use of asymmetric capabilities, the ability to strike the enemy even when surface fleets are unable to leave port – or engaged elsewhere – would be invaluable. Asymmetry, therefore, should not only be measured in absolute terms while comparing two forces at a global level, but as a fluid ratio which may vary in time and place. Indeed, just because asymmetric warfare is an obligation for some, it does not mean it cannot be a choice for others.
Elio Calcagno is a defence analyst based in Rome. He currently works as researcher in IAI’s ‘Defence, security and space’ programme, where he focuses in particular on the policy, industrial, strategic and operational aspects of defence at the national, European and NATO levels.
To stay up to date with The Broadside, please subscribe or pledge your support!
What do you think about this article? Why not leave a comment below?
True to a T. And Royal Navy itself did not hesitate to embrace assymetric with frogmen and kayaks and X-craft both in Europe (Tirpitz) and in Asia (Singapore)