4. British maritime power
The United Kingdom’s identity and global influence have long been shaped by its maritime character. From imperial naval supremacy to leadership in global shipping services, Britain’s power has historically relied on the sea.
This chapter explores the geographical, historical, and strategic foundations of British maritime power, while also examining the contemporary challenges it faces in maintaining influence over global maritime affairs.
#1. Foundations of British sea power: maritime spaces as vectors of economic and military strength
#A. Geographical foundations
#a) An insular country wide open to the sea
The United Kingdom, as an island nation, is fundamentally shaped by its maritime geography. Comprising two principal islands, one of which is the largest in Europe, along with thousands of smaller isles, the UK possesses a coastline extending over 12,400 kilometres. This is notably more than three times the length of the French metropolitan coastline, which measures approximately 3,400 kilometres. Such extensive coastal access offers the UK significant connectivity to major maritime domains, including the North Sea, the Irish Sea, the English Channel, and the Atlantic Ocean.
The UK's geographic position is critical to the control of key maritime routes linking Northern Europe to the Atlantic Ocean and the Mediterranean Sea. This strategic leverage is exemplified by three major maritime chokepoints. Firstly, the Strait of Dover, one of the busiest seaways in the world, facilitates the transit of approximately 400 commercial vessels per day. Secondly, the GIUK gap (Greenland, Iceland, and the UK), is a vital passage through which Russian or Chinese vessels must travel when moving from the Arctic into the Atlantic. For the Royal Navy, this corridor is of paramount strategic value, any attempt by northern European powers to reach the open Atlantic must navigate either the heavily defended English Channel or one of the GIUK exits surrounding Iceland.
Furthermore, the UK’s sovereignty over Gibraltar significantly enhances its maritime command. Located at the entrance to the Mediterranean, the Strait of Gibraltar is a narrow waterway just 14.3 kilometres wide. Gibraltar itself hosts a British Overseas Territory comprising a city, a naval base, and a Royal Air Force installation. As a result, the UK holds strategic influence over a vital global shipping route. It is worth noting that only Spain, France, and Portugal have direct access to the Atlantic Ocean that cannot be readily controlled via British-held maritime chokepoints.
The UK's Exclusive Economic Zone (EEZ) also plays a role in its maritime power. While oil and gas extraction in the North Sea has declined to roughly a third of its peak output, the country is a global leader in renewable offshore energy. The UK hosts seven of the ten largest offshore wind farms globally, with wind energy contributing around 20% of its electricity supply.
However, the exploitation of fishery resources within British waters remains relatively low. In 2019, for example, the fishing industry employed only about 12,000 individuals, indicating a modest level of development in this sector compared to the UK's broader maritime capabilities.
#b) The global reach of the British Overseas Territories
An often-overlooked dimension of British maritime power lies in its global network of Overseas Territories. The United Kingdom maintains sovereignty over 14 British Overseas Territories (BOTs), which collectively grant it the fifth largest EEZ.
#Uninhabited or research/military territories
| British Overseas Territory | Region |
|---|---|
| British Antarctic Territory | Antarctica |
| British Indian Ocean Territory | Indian Ocean |
| South Georgia and the South Sandwich Islands | South Atlantic |
#Sovereign military base areas
| British Overseas Territory | Region |
|---|---|
| Sovereign Base Areas of Akrotiri and Dhekelia (Cyprus) | Eastern Mediterranean (Cyprus) |
#Civilian-populated, self-governing territories
| British Overseas Territory | Region |
|---|---|
| Anguilla | Caribbean |
| Bermuda | North Atlantic |
| British Virgin Islands | Caribbean |
| Cayman Islands | Caribbean |
| Falkland Islands | South Atlantic |
| Gibraltar | Southern Europe / Mediterranean |
| Montserrat | Caribbean |
| Pitcairn Islands | South Pacific |
| Saint Helena, Ascension and Tristan da Cunha | South Atlantic |
| Turks and Caicos Islands | Caribbean |
This maritime extension not only amplifies the UK's geopolitical footprint across several oceans but also serves as a key component of its environmental and strategic ambitions.
Remarkably, approximately 90% of the UK’s biodiversity is located within these territories, underscoring their critical ecological value. From coral atolls in the Indian Ocean to sub-Antarctic islands, the environmental diversity of the BOTs offers the UK a unique platform from which to advance global conservation efforts.
In line with this ecological imperative, the UK has increasingly sought to assert itself as a leader in marine environmental protection. One of the most prominent expressions of this commitment is the Blue Belt Programme, the UK's flagship initiative for marine conservation. Launched to support the sustainable management of ocean spaces under British jurisdiction, the programme has established over 4 million square kilometres of Marine Protected Areas (MPAs) across seven British Overseas Territories. These MPAs represent some of the largest such areas globally and contribute significantly to international biodiversity preservation and climate resilience.
This maritime conservation strategy not only reflects growing environmental concerns but also reinforces the UK’s soft power and global standing in post-Brexit foreign policy. By investing in marine sustainability across its territorial network, the UK leverages its historical and geographical legacy in pursuit of contemporary ecological leadership.
#c) An insular country dependent on its ports
As an island nation, the United Kingdom remains heavily reliant on maritime transport for its economic vitality. Approximately 95% of the country’s trade by volume is conducted through maritime routes, underscoring the critical role of seaports in facilitating the UK's integration into global supply chains and commercial networks. However, despite this overwhelming dependence on maritime trade, the UK does not possess a port infrastructure proportionate to its trading volumes when compared to continental Europe.
The relative modesty of Britain’s port system can be attributed to its reduced hinterland and the geographical constraints of an island economy. Unlike many continental ports which benefit from vast inland markets and extensive rail and road connections, British ports often serve more compact regional economies. A salient example is the Port of Felixstowe, situated in the Southeast of England. It is the UK’s busiest container port, handling approximately 50% of the nation’s containerised cargo. Yet on the European scale, Felixstowe ranks only as the eighth-busiest port, trailing behind larger continental hubs such as the ones in the Northern Range (Rotterdam, Antwerp, and Hamburg) which serve much broader economic catchments.
This contrast highlights a structural limitation in the UK’s maritime infrastructure. While strategically positioned for global maritime flows, especially across the North Atlantic and through key chokepoints, British ports operate within a system that is comparatively decentralised and spatially constrained. Consequently, the UK's ability to maximise its maritime advantage is often tempered by the physical and logistical realities of its geography.
#B. Historical foundations
The maritime strength of the United Kingdom is deeply rooted in its historical legacy as the pre-eminent sea power of the nineteenth century (splendid isolation). During this period, Britain established unmatched supremacy through a combination of naval dominance, global trade networks, and maritime services infrastructure. This inheritance continues to shape the country’s geopolitical posture and maritime identity in the twenty-first century.
Britain's leadership as the world’s foremost maritime power was grounded in three interrelated pillars: the Royal Navy, a formidable merchant navy, and a robust sector of maritime professional business services. While the Royal and merchant navies once symbolised Britain's global reach and imperial authority, it is the maritime professional services sector, comprising legal, insurance, ship broking, and financial services, that remains a domain in which the UK retains global leadership today.
#a) Royal Navy: still a world naval power, albeit in relative decline
Despite a gradual erosion in relative strength, the Royal Navy continues to represent a significant component of Britain’s global influence. It maintains two aircraft carriers, including the HMS Queen Elizabeth, which is the largest warship ever built for the Royal Navy and ranks as the first in Europe and third in the world by size. This is complemented by the UK’s strategic nuclear deterrent, which consists of four nuclear-armed submarines operating under the Trident programme. Within Europe, only France and the UK possess nuclear deterrent capabilities, placing them among an exclusive group of just nine nations globally.
In terms of expenditure, the UK is the seventh-largest naval defence spender in the world. However, this position masks a long-term decline in defence investment and human resources. Defence spending as a percentage of GDP has decreased significantly, from approximately 4% in 1990 to around 2.6% today, mirroring reductions in personnel and operational capacity.
Nonetheless, the Royal Navy maintains a strategic global presence through a network of overseas bases. One key example is its permanent base in Bahrain, which serves as the operational hub for Royal Navy activities in the Persian Gulf, Red Sea, and Indian Ocean. Such deployments reflect a broader historical pattern: British military power has traditionally been projected from the sea and by maritime means. This enduring relationship between naval capacity and national power continues to inform Britain’s defence strategy and its role on the international stage.
#b) Decline of the UK’s commercial fleet
While the UK once presided over the world’s largest merchant navy, its commercial fleet has undergone a profound decline, reflecting broader shifts in global maritime economics and regulation. Today, British-flagged vessels account for a mere 1% of the world’s commercial fleet, a stark contrast to the nation’s former maritime dominance during the colonial era.
This erosion is the result of intensified competition from both European neighbours and emerging maritime powers. Countries such as China, South Korea, Singapore, and Greece have developed robust commercial fleets backed by favourable fiscal regimes, large-scale shipping conglomerates, and substantial state support. In this context, the UK has failed to maintain a competitive edge. Notably, no British shipping company features among the global top 100 maritime operators, underscoring the sector’s diminished international relevance.
Another significant factor in this decline is the widespread use of flags of convenience. Approximately two-thirds of vessels owned by UK-based interests operate under foreign flags, often registered in jurisdictions such as Panama, Liberia, or the Marshall Islands. These arrangements allow shipowners to benefit from lower labour costs, looser environmental regulations, and reduced taxation. While economically rational from a business perspective, this practice undermines the visibility and strategic influence of the UK’s commercial fleet and reduces its contribution to national employment and fiscal revenues.
The decline of Britain’s merchant navy thus illustrates the broader transition of the UK from a maritime empire to a service-oriented economy, where historical maritime prestige no longer translates into contemporary commercial dominance at sea.
#c) The UK’s leadership in maritime services and global governance
Despite the decline of its merchant fleet, the United Kingdom continues to exert substantial influence in the global maritime sphere through its leadership in shipping-related services and maritime governance. London, in particular, has emerged as a global decision-making centre for maritime transport, offering a comprehensive ecosystem of legal, financial, and logistical services that underpin international shipping operations.
The city hosts the headquarters of the International Maritime Organisation (IMO), a specialised agency of the United Nations responsible for regulating international shipping. The presence of the IMO not only reinforces London's centrality in maritime policy making but also symbolises the UK's enduring role in shaping global maritime norms and standards.
Moreover, British maritime law retains a dominant position in the resolution of international shipping disputes. An estimated 80% of such disputes are settled under British legal frameworks, and the vast majority are arbitrated in London. This legal pre-eminence enhances the UK's authority in the sector and attracts shipping firms from across the world to use British jurisdiction as a neutral and trusted platform.
The UK also commands a leading share of the global market in maritime professional business services. Approximately 25% of these services, ranging from maritime insurance and legal consultancy to ship broking and financial advisory,are conducted through British firms. London is home to seven of the world’s twenty largest ship broking companies, consolidating its status as a global maritime hub. Maritime insurance, particularly through institutions such as Lloyd’s of London, further exemplifies the city's critical role in managing and mitigating the financial risks associated with global shipping.
In sum, the UK’s maritime influence has evolved from a focus on physical fleets to a sophisticated dominance in the infrastructures that support global maritime operations. This transformation underscores the resilience and adaptability of Britain’s maritime tradition in the face of shifting geopolitical and economic tides.
#2. The UK's challenged global role in maritime affairs
#A. Competition from other maritime powers and European states
Despite its rich maritime heritage and global service leadership, the United Kingdom’s contemporary maritime influence faces increasing challenges from both traditional allies and emerging maritime powers. One major dynamic shaping this shift is the UK’s growing dependency on the naval capabilities of the United States. While the Royal Navy retains significant strategic assets, its reduced scale and operational reach have led the UK to align more closely with US-led naval initiatives, particularly within NATO and in global maritime security operations.
Moreover, the UK's maritime registry has become less attractive in the face of competition from European counterparts. Norway, for example, offers a more favourable fiscal environment for ship registration, with lower tax burdens and more flexible regulatory conditions. As a result, the Norwegian flag has become more appealing to shipowners, contributing to the decline of the UK-flagged commercial fleet.
These developments reflect a broader trend: while the UK remains influential in maritime law and services, its direct control over maritime logistics and naval autonomy is increasingly constrained by external economic and geopolitical pressures.
#B. Strategic competition from emerging countries
The UK’s maritime influence is also increasingly challenged by the rise of emerging powers, particularly in the Indo-Pacific region. These challenges manifest in both economic and strategic dimensions.
In the domain of maritime commerce and logistics, the UK faces intense competition from global port cities such as Singapore, Shanghai, and Hong Kong. These Asian metropolises have developed into major international hubs for shipping, port management, and maritime services. Their advanced infrastructure, competitive regulatory frameworks, and integration into global supply chains have diminished the UK's comparative advantage, particularly that of London’s historical dominance in maritime finance and services.
Strategically, the contest for control and influence over key global choke points has intensified. The South China Sea and the Strait of Malacca, critical arteries of global trade, have witnessed the assertive rise of Chinese military power. This poses a direct challenge to the UK’s maritime interests, traditionally protected through a network of military bases and intelligence-sharing arrangements in former colonies, notably Singapore, Malaysia, and Brunei.
In response to growing Chinese militarisation, the UK has reaffirmed its commitment to the defence of freedom of navigation. British naval forces have participated alongside the United States and France in Freedom of navigation operations (FONOPs) in the South China Sea, aiming to uphold international maritime law and counter excessive territorial claims. However, such actions have provoked strong reactions from China, which has perceived the deployment of UK aircraft carriers in the region as a potential military threat, raising the risk of escalation.
At the same time, recent incidents have exposed the limitations of the UK’s power projection. A notable example occurred in the summer of 2019, when Iranian forces seized a British-flagged oil tanker in the Strait of Hormuz. Despite its formal maritime commitments, the Royal Navy was unable to prevent or reverse the incident, highlighting constraints in operational capacity and global reach.
These developments underscore the complex reality of the UK's maritime posture in the 21st century: while committed to upholding international norms, it must navigate a multipolar maritime order where its relative capabilities are increasingly tested by rising powers.
#C. Maritime challenges arising from Brexit
The UK’s withdrawal from the European Union has introduced new complexities into its maritime affairs, particularly with regard to regulatory frameworks, border controls, and trade flows. One of the most immediate consequences has been the emergence of tensions with EU member states, notably France, over fishing rights within the UK's EEZ. French fishermen have encountered difficulties in securing licences to operate in UK waters, leading to diplomatic friction and periodic maritime disputes.
Brexit has also imposed logistical and financial burdens on maritime trade between the UK and continental Europe. The reintroduction of customs checks and regulatory divergence has resulted in increased transit times and higher costs for goods passing through British ports. These disruptions have affected not only major commercial ports but also smaller regional hubs, thereby challenging the efficiency and competitiveness of the UK's maritime trade infrastructure in the post-Brexit era.
#D. Maritime implications of potential territorial fragmentation
The integrity of the UK’s maritime power is further challenged by internal political dynamics, particularly movements advocating for independence within its constituent nations. Scotland’s renewed drive for independence, fuelled in part by its desire to rejoin the European Union, presents a significant geopolitical and maritime dilemma for the UK.
An independent Scotland could profoundly alter the strategic and economic landscape of British maritime policy. Firstly, it would entail the loss of direct access to substantial hydrocarbon resources located in the North Sea, which have long been a component of the UK’s energy portfolio and economic strategy. Secondly, a redrawing of maritime boundaries would affect the UK’s EEZ, diminishing its jurisdiction over fishing, mineral, and energy resources in northern waters.
Strategically, one of the most critical consequences would be the potential loss of control over the GIUK gap. The GIUK gap remains essential for monitoring naval movement between the North Atlantic and the Arctic, particularly in the context of renewed great power competition. Losing sovereign control over this area would weaken the UK’s ability to act autonomously in Atlantic defence and surveillance operations, increasing its dependence on NATO coordination and allied cooperation.
Thus, territorial fragmentation, particularly through Scottish independence, poses not only constitutional challenges but also a redefinition of the UK’s maritime geography and its capacity to operate as a cohesive maritime power.
#E. Disputed maritime claims and contested sovereignty over EEZs
The United Kingdom’s assertion of sovereignty over several maritime zones is increasingly contested, raising complex legal, diplomatic, and geopolitical challenges. Two of the most prominent disputes, concerning the Falkland Islands and the Chagos Archipelago, have brought international scrutiny to the UK's control over its overseas territories and the maritime resources surrounding them.
In the South Atlantic, the Falkland Islands remain at the centre of a longstanding sovereignty dispute between the UK and Argentina. While the islanders have repeatedly affirmed their desire to remain under British sovereignty, their position is partly motivated by the anticipated benefits of offshore hydrocarbon exploration in the surrounding waters. However, in 2016, the United Nations Commission on the Limits of the Continental Shelf (CLCS) issued a decision that supported Argentina’s claim to an extended continental shelf, which would encompass waters currently under British control. Although the UK does not recognise the CLCS ruling, the decision has added international weight to Argentina's claims.
In the Indian Ocean, sovereignty over the Chagos Archipelago, including Diego Garcia, has been awarded to Mauritius by the International Court of Justice (ICJ) and supported by a UN General Assembly resolution in 2019. The ICJ ruled that the UK’s separation of Chagos from Mauritius during decolonisation was unlawful and called for its return.
Despite growing international recognition of Mauritian sovereignty, including a symbolic Mauritian expedition and flag-raising in 2022, the UK has maintained de facto control, arguing that the ICJ opinion is non-binding. Today, the handover remains complex due to the US military base on Diego Garcia, which is vital to Indo-Pacific strategy, and the unresolved displacement of the Chagossian population, forcibly exiled in the 1960s.
The case illustrates the limits of the UK’s maritime sovereignty amid evolving international legal standards and post-colonial challenges.