The Black & Red Sea Lessons

Over the last two years, warfare at sea has been conducted at a higher level of intensity than has been seen for decades. The conflict in Ukraine, in which the Russian Black Sea Fleet was rendered “functionally inactive” by a country without a surface fleet, and the ongoing battle in the Red Sea have provided analysts and practitioners of naval warfare with a wealth of empirical evidence. It is thus germane to consider what lessons the Royal Navy might draw from these conflicts as the force continues a process of recapitalisation which will extend into the 2030s.

The Anti-Access/Area Denial Threat: A Challenge to be Contextualised

The remarkable success enjoyed by an overmatched Ukrainian Navy and the country’s security service against Russia’s Black Sea Fleet has, understandably, led some to ponder the question of whether we are approaching a tipping point in the conduct of warfare at sea. The ability of the Ukrainians to combine anti-ship cruise missiles, uncrewed surface vessels and land attack missiles such as Storm Shadow into a layered anti-access area denial threat that has partially forced the Russian Navy out of Sevastopol raises important questions regarding the risks which surface vessels face, particularly in confined waters. The proliferation of these capabilities, many of which are now employed by weaker states and indeed non-state actors, will mean that what would have been largely uncontested deployments at sea in the past will involve contested theatre entry.

However, claims regarding the risk to surface combatants themselves should be scrutinised. In the Black Sea, despite high losses in aggregate, the Russian fleet has not endured a historically high loss rate. Over the course of the two and a half year conflict, Russia has lost 22 vessels, which amounts to a loss rate of 0.03 per 100 ship days in theatre. For reference, the US loss rate against Japanese Kamikazes off Okinawa was roughly 0.2 per 100 ship days (with vessels sustaining damaging hits at a rate of 0.44 per 100 ship days), and the UK task force in the Falklands endured 1.35 damaging hits per 100 ship days – despite which both navies prevailed. In effect, then, it is not clear that the vulnerability of vessels to the anti-access threats of yesteryear, be they crewed suicide aircraft or Exocet missiles, was less acute than is the case now. The importance of not overstating the risks to surface vessels has been reinforced in the Red Sea, where the Houthis have thus far failed to successfully engage a coalition surface combatant and where UK and US vessels have enjoyed tactical successes against complex salvos incorporating capabilities such as C-802 anti-ship missiles, Samad-3 UAVs and Asef anti-ship ballistic missiles.

Even so, a limited loss rate can have crippling cumulative effects on a fleet over time, as it has had on the Russian Navy. This is true of all forces, but the risk is especially acute in maritime warfare as vessels are increasingly difficult to replace. This in many ways reinforces a classical principle: if a navy has a choice between seeking decision early (even at some risk to its forces) or conserving capability, it should generally opt for the former option. A conservative approach creates false efficiencies, reducing loss rates at any given time but raising the risks of a long war which many navies may not be able to sustain, irrespective of how low they can keep their loss rates. Of course, a navy cannot always force a decision in war – in truth, there was no way the Russian navy could have shortened the conflict. However, its losses in a long war still reinforce the lesson.

If a navy has a choice between seeking decision early (even at some risk to its forces) or conserving capability, it should generally opt for the former option

While in both the Black Sea and the Red Sea large surface combatants have been relatively safe, the same cannot be said for less heavily armed vessels and the fixed infrastructure that supports the fleet. Many of Ukraine’s successes have been achieved against platforms such as the Ropucha-class landing ship (which serves as a logistical workhorse for the Russian army) as well as minesweepers and patrol boats. In the Red Sea, the Houthis have enjoyed a comparatively high hit rate against merchant shipping. While warships themselves may not be more vulnerable, the threat that anti-access systems pose will be most acute for the lightly armed (or unarmed) oilers and solid support vessels that enable the Royal Navy’s operations. The effect of this will be significant when limited numbers of support vessels are available. Additionally, while tasks such as mine countermeasures have always had to be conducted under some risk of an air threat, the UK’s (Royal Fleet Auxiliary-operated) mine countermeasures vessels will face an increasingly multilayered anti-access challenge, incentivising uncrewed solutions which can be employed from greater distances and multiple vessel types.

Fixed infrastructure has also proven vulnerable even under optimal conditions. The ability of Ukraine’s armed forces to progressively target both vessels and structures in Sevastopol, which is defended by a robust integrated air defence system, illustrates that over time even relatively well-defended fixed bastions will be challenged by cruise and ballistic missiles, among other threats. For the UK, home ports such as Portsmouth are relatively safe. In the absence of a Russian intermediate-range ballistic threat, the primary threat is posed by cruise missiles, which – if launched from the eastern flank – would have to traverse a considerable amount of territory. There is a real threat posed by cruise missiles launched from Russian bombers, surface vessels and submarines from the northern flank, although even in this case, once an Allied maritime component command is stood up, the vulnerability could only be exploited if Russia was willing to risk losing key strategic assets. At home, the risk is likely to be most acute in the early stages of a conflict. That said, key seaports of disembarkation on which elements of the Royal Navy (and the wider UK joint force) would depend in an expeditionary context are far more vulnerable by dint of proximity to likely theatres of combat. Examples include Duqm in Oman and Gothenburg in Sweden. The latter, as Scandinavia’s largest port, has been an important logistical lynchpin of exercises such as Trident Juncture, which included the Royal Navy and Marines.

The way in which Russia had to eventually defend Sevastopol with not just air defences but also helicopters and barriers (to respectively slow and engage UAVs) also carries more tactical lessons. Of note is the important role played by Russian helicopters and fixed-wing aircraft against unmanned surface vehicles (USVs), which are able to remain below a surface vessel’s radar horizon for extended periods, but which are vulnerable to air attack. This could have ramifications for the Royal Navy’s Merlin and Wildcat fleet, which will also be needed to support other functions such as anti-submarine warfare (ASW), among other tasks. The addition of roles for an already stretched helicopter force might be avoided through the use of autonomous systems, and engaging surface targets in clutter may be an area where machine learning and computer vision – as well as the non-lethality of the engagement – can allow autonomy to be exploited quickly (as contrasted with more complex tasks such as ASW).

The risk to logistical nodes will reinforce another challenge: the difficulty of achieving magazine depth. This is partially a function of cost, since interceptors such as the Aster-15 and 30 cost much more than many of the missiles they may have to intercept. It is also, however, a function of the fact that vertical launching systems (VLS) cannot be safely replenished at sea in even moderate sea states. The likelihood that vessels will expend their VLS loadout, coupled with a risk to any allied or sovereign forward bases on which they may have planned to rely, could – in extremis – force the rotation of Royal Navy vessels to home ports, significantly impacting their operational tempo. Fleet sustainment, rather than protection, may be the biggest challenge in contested theatres.

A final notable feature in both the Black and Red Sea has been the role of third-party ISR provision. While the extent of the Allied role in providing ISR to Ukraine in the Black Sea cannot be known, it is understood that the US is providing data from space-based ISR to Ukraine 32 times per day, and that Western surveillance platforms have conducted patrols over the Black Sea. In the Red Sea, Iranian special-purpose vessels such as the Behshad have provided cueing to Houthi missile batteries ashore, a role also performed by the Iranian vessel Saviz during the Saudi-led coalition’s campaign. A sub-peer opponent backed by a state source of adversary ISR that cannot be targeted for political reasons will pose a challenge to many concepts for countering anti-access/area denial (A2AD) which depend on destroying or crippling an opponent’s sensors (which may not be an option in indirect conflict). A range of options of varying complexity and risk – from jamming and cyber attacks to covert sabotage (likely conducted against the Saviz by Israel) – are available to navies, but the risks and costs of these options need to be weighed ahead of time as do the cross-service and cross-government dependencies they create.

Lessons Regarding the Pacing Opponent

The two conflicts have also illustrated a number of things about putative opponents that the Royal Navy may face, most notably Russia.

Russia’s failures in engaging dynamic targets at sea over the course of the Ukraine conflict have been considerable. To use one example, the Russian navy and air force failed to fix and engage the Ukrainian navy’s last surface vessel – the Yuriy Olefirenko – for months, even when it was deployed at relatively close proximity to Kherson to provide naval gunfire support. The inability to engage the vessel at sea (it was eventually sunk in port), despite Russia enjoying air and naval superiority in the Black Sea during 2022, would appear illustrative of broader problems with aggregating data from multiple sensors and tasking platforms dynamically. This may reflect challenges in the stated desire to aggregate information from multiple service branches without reaching back to a higher headquarters or involving multiple separate command chains. While the failure to track a relatively conspicuous amphibious vessel was likely a failure of organisational structures rather than sensors, Russia will struggle in the latter regard as well. Though it aspired to replace the Soviet-era Tselina and Legenda constellations with a robust network of Pion-NK, Lotos and Persona satellites equipped with ELINT, COMINT and EO sensors, it had by 2021 launched only one Pion-NKS satellite, and fields a very limited EO capability. In the absence of a space-based ISR capability, Russia’s ability to track dynamic targets at long distances (except through very non-granular tools such as the Polsodnukh-E OTH radar) will be limited.

In this context, the methods which NATO has used to employ maritime power as an asymmetrical competitive tool vis Russia – including the deployment of ELINT spoofing on islets in the Aegean during the Haystack exercises and Ocean Venture, which saw emissions-dark carrier operations in Norway (where terrain added an additional layer of complexity to air-based tracking) – may be tactically feasible vis a Russia that does not employ the sophisticated A2AD capability that China does. Towards the end of the Cold War, an inability to perform dynamic tracking led the commander of the Soviet Northern Fleet to request a trebling of his budget, and was a major factor in Soviet assessments of the conventional balance. This is, in principle, good news for a Royal Navy that will be built around aircraft carriers for the foreseeable future. However, the ability to perform these actions during the Cold War depended in great measure on US aircraft carriers and was, moreover, a product of sustained training in complex waters such as those on the Norwegian coastline where operating large vessels requires considerable skill. Any European effort to replicate this (of which the Royal Navy could be an important part) would need to account for fewer available US capabilities in the event that the Indo-Pacific absorbs more capacity. Munitions sustainment and enablement will have to be accounted for, particularly given the small numbers of munitions capable of suppression of enemy air defences, such as SPEAR-3, that are likely to be available. In effect, then, Cold War concepts for employing forces forward to impose multiple dilemmas on a continental power remain tactically valid, but this will only be true if they can be resourced.

Many of the challenges of greatest significance relate to generating the capacity to leverage existing capabilities and competencies effectively

Another major lesson regarding the Russian navy as an opponent, which became particularly stark after the loss of the Moskva, is that the Russian navy is designed to have strategic effects from relative proximity to its ports. From positions in Crimea, the Russian fleet – which is the only service equipped with the 3M-14 Kalibr cruise missile – has been a key component in Russia’s strike campaign against Ukrainian civilian infrastructure which is fixed and easier for Russia to target with complex salvos. Ukraine has progressively degraded this threat, but at a likely considerable cost in missiles. While it is not known exactly how many Storm Shadow/SCALP and Neptune missiles have been used against Russian ports, it is understood that 300 missiles were provided to Ukraine and that striking the Black Sea Fleet was a priority line of effort for Ukraine’s strike campaign. Moreover, each reported cruise missile strike appears to have been preceded by days of attacks using UAVs, possibly alongside other shaping activity. For navies such as the Royal Navy (and indeed the UK joint force), the challenge is not that sinking the Russian surface fleet will be inherently difficult, but rather that if the fleet opts to launch cruise missiles against civilian infrastructure from positions close to air defence networks in Kaliningrad and the northern bastion, there will be a political demand to engage it (irrespective of the military value of doing so) and the task will be a burden in terms of both planning and munitions expended. Given the likely demand for standoff munitions elsewhere in the theatre, this is of importance. Surface strike, then, is a priority line of effort even if the Russian surface fleet is a decrepit force. The requirement to engage targets within well-defended bastions while accounting for limited VLS capacity into the 2030s, even after vessels such as the Type 26 and Type 31 enter service, will make it of particular importance that weapons such as FC/ASW are able to achieve a high Single Shot Probability of Kill in defended airspace, since the smaller a salvo, the more important penetration and successful engagement becomes. Though Russia’s nuclear-powered submarines are its most potent capability, the Russian naval threat is not just a submarine threat.

Conclusions

The conflicts in the Red Sea and Black Sea carry a number of important lessons which might inform the Royal Navy’s efforts to generate its future fleet. In many ways, the technological dimensions of these conflicts – though the most heavily studied – have been less important than the fundamental lessons that they carry regarding how a fleet must structure and prioritise tasks to prepare for major contingencies. The lessons learned from these conflicts, then, have an evolutionary quality where many of the challenges of greatest significance relate to generating the capacity to leverage existing capabilities and competencies effectively. Technology can be an important enabler in this regard, but is not a solution in itself.

Sidharth Kaushal is Research Fellow for Sea Power at RUSI. His research at RUSI covers the impact of technology on maritime doctrine in the 21st century, and the role of sea power in a state’s grand strategy.