The sea makes us one

Henk Warnar

Increasing support exists for the view that European navies should stay clear of Indo-Pacific waters and focus on the defense of Fortress Europe. In War on the Rocks, Tim Sweijs and Paul Van Hooft argue that Europe should face the two-theater tragedy and accept that too high ambitions create the risk of sleepwalking into a third world war. Such views underappreciate the nature of sea power, argues Henk Warnar.

Too often, sea power is seen as escalatory and destabilizing. It’s insufficiently understood that the value of sea power is determined by its flexibility to move between different theatres, and  the contribution of naval forces to coalition operations and its role in crisis management in order to prevent major war is undervalued. This article discusses these elements of sea power (stability, geography and international relations) and argue that it is in the interest of Europe to exploit and benefit from these sea power characteristics to strengthen its autonomy and defend its interests. The sea can enable Europe not only to make it a stronger Union but also to carry its influence in a globalized world, flowing via the seas that connect different worlds and theatres. As stated in a mariner’s slogan: the sea makes us one.

It would be too simplistic to classify sea power as either escalatory and destabilizing or de-escalating or stabilizing. Sea power is only an instrument and its effects will predominantly be determined by the intent of the user and the circumstances. In 2020, issue 4 of journal Security Studies was entirely dedicated to the ‘New Era of Maritime Competition’ but views on this matter differed widely. Some views focus on the doctrinal nature of naval warfare, in which the challenge to be ‘the first to fire effectively’ is an important factor for determining success in battle. This characteristic, particularly under the circumstances that often the difference between offensive or defensive intentions can be hard to distinguish, could create the risk of accidental or unintended escalation. Other views demonstrate that democratic countries have often used their navies for coercive purposes to settle disputes. These disputes, in contrast to territorial disputes, are also more often settled through multilateral institutions. Furthermore, maritime disputes less frequently turn into militarized incidents with fatal casualties than territorial disputes.

Sea power is often blamed to stimulate arms races. Samuel Hunting identified 13 arms races, of which 7 were naval. However, only one (United States vs Japan, 1934-1941) resulted into war. Imperial Germany’s battlefleet was often associated with Wilhelmine militarism, but it wasn’t the German Fleet that made the United Kingdom (UK) decide to land forces on the continent: It was the Schlieffen plan and territorial aggression. Conversely, it wasn’t Tirpitz’ plan to defeat the British fleet but to deter the UK from intervention. Deterrence may not always be successful, however, such failure is not yet an argument to dispel it. Preceding the Russian invasion in Ukraine, NATO had assembled a huge deterrent fleet in the Mediterranean. It signaled NATO’s resolve to defend its territory but couldn’t prevent the invasion. Withdrawal of the fleet from the Mediterranean signaled NATO’s desire not to escalate but simultaneously, the concentration of NATO warships in the Baltic Sea Region signaled a strong message not to invade the Baltic States or Poland. In this way, NATO’s fleet was a useful instrument to limit and contain the conflict despite Russian aggression.

In the Indo-Pacific region, preventing great power escalation is a complicated matter in which naval forces play an important role. European-Asian economic interdependence implies a vested interest for Europe including the Netherlands to be involved militarily. The most dangerous, but nonetheless possible, condition is when China perceives resistance to an invasion into Taiwan to be weak because of insufficient commitment by Taiwan’s allies. Deterrence towards China should be credible but it needs careful handling. Large fleet maneuvers, such as the 2021 four allied carriers supported by Dutch Warship Evertsen operating together in the Philippine Sea, invites Chinese reactions in the form of large numbers of intimidating fighter sorties over Taiwan. A comparable crisis occurred in 1996 when a US carrier passed through the Taiwan strait and the crisis in 2022 when Nancy Pelosi visited Taiwan.

In these events sea power can be a controllable instrument to deliberately increase tension to deprive an adversary of room to maneuver. It serves as a mechanism that can be used to prevent China taking advantage of the war in Ukraine and undertake military action towards Taiwan creating a fait accompli. So far, this strategy has been successful, although there is no guarantee as to how it will work in the future. A strategy to stay away from the problem may appear careful, but it would also deny any effort to handle the problem. Europe’s posture and policy will differ from the US’. European naval participation, whatever the size, will be an opportunity to influence the without making the crises more dangerous.


The land- and maritime domain differ fundamentally in how to maneuver in the battle space. On land it is possible to use obstructions and fortify for defense. Space creates depth and frontlines structure the battlefield in separated zones. At sea the attacker and defender usually have equal access to space and in  the high seas the defender doesn’t enjoy the advantages of defense that often exists on land. Both sides often move in the same waters. In history,  maritime countries such as England and to a lesser extent the United States, often fought continental powers such as Napoleonic France, Germany or Russia. Current competitors such as China and Iran are also continental by nature. Continental powers are surrounded by waters that shape their confrontations. A maritime power enjoys freedom to maneuver, can exploit surprise and is free to choose its preferred site to project power whereas a  continental power needs to spread out its naval forces covering all shores for their defense.

This asymmetry determines the differing nature of the problem of how to concentrate or disperse naval forces. The continental power will need to concentrate its dispersed forces to enable a decisive blow. For example Russia, before the attack on Ukraine, moved Ropucha amphibious warships from the Northern and Baltic fleets towards the Black Sea, and a surface task group around cruiser Varyag from the Pacifc fleet towards the Mediterranean. Although maritime powers usually have smaller armies, the sea permits them to attack the continent from different angles forcing the continental opponent to reposition or spread out its army. Napoleon fought wars in both Russia and the Iberian Peninsula. During the Russian civil war (1918-1921) the UK intervened by attacks in the Baltic, and in the White, Black and Caspian seas.

A maritime power may have its naval forces spread out over a large area, but most important is that all naval actions are synchronized towards a specific objective. Because the maritime power will often lack a massive army to directly overwhelm its opponent’s capital or other center of gravity, it will often prefer a long-term strategy, for example to exhaust an enemy with economic warfare. During the Crimean war decisive results were achieved by Russia’s economic breakdown as a result of blockades in the Baltic and operations in the White Sea and the far East, which all complimented the Crimean campaign.

Flexibility and mobility

The sea is connecting all different theatres. In this globalized world it’s an illusion that a crisis in a particular region can be solved when ignoring effects elsewhere. The impact on Dutch economy from a blockade of the Malacca strait in Asia will not be very different from a blockade of the nearby Channel. Particularly in a multipolar setting, connectedness creates opportunities to take advantage of a conflict in another sphere/on another stage. During WWII, campaigns in the Pacific and in Europe directly influenced each other. The Europe-first-approach forced the US to delay Pacific operations. Also, fighting operations between two belligerents can take place in far territories. In both WWI and WWII, Germany started by attacking British sealines of communications in the Pacific and/or South America. Additionally, during the 18th century 7-Year War, most naval combat between France and England occurred in the Western hemisphere.

Warship or strategy design should therefore not be optimized for task x in area y but instead allow for flexibility and mobility. In 2005, as part of the Marine studie, multipurpose frigates were sold in order to build Holland class patrol vessels designed for coastal waters around the Dutch West Indies islands and the North Sea. As a result, during the Gaza crisis in 2024, HNLMS Holland could be deployed to support humanitarian assistance. During the crisis, naval action was required elsewhere in the Red Sea in response to Houthi attacks on merchant shipping. Unfortunately, the specialized design made the ship unable to conduct air defense operations preventing a redeployment to the Red Sea where action was most needed.

The current multipolar world provides security risks that are scattered all over the globe. Facing an expanding Chinese navy in combination with trends that warships rise in levels of technological sophistication and costs, but drop in numbers, European countries cannot afford a suboptimal regional employment of naval forces. Western countries witness a challenge in number but combined, numbers are sufficient to cover all threats as the following table illustrates.

Table 1. Combatant Vessels among Major International Powers and Groupings. From CSIS, Are European Navies Ready to Navigate an Ever More Contested Maritime Domain?, 2023 p16.

However, these numerical advantages, can only be exploited if sufficient cooperation exists. This draws attention to the third characteristic of naval capabilities, the suitability to support coalition building and its default mode of allied operations.

Coalition operations

The purpose to construct and maintain alliances against an opponent has always been fundamental in naval thought. In his Green Pamphlet (p336), Julian Corbett defined ‘the prevention or securing of alliances’, alongside commerce warfare and power projection ashore, as one of the three strategic functions of the fleet. In his Spectre of navalism Corbett described the Pax Britannica as a liberal world order in support of free trade, that was threatened by German militarism. Democracies have no interest in war, as war is bad for business. The French naval scholar Admiral Castex described cooperation among western nations, whose navies would oppose the continental, mystic and fanatic threat of aggression from a troublemaker, initially Germany and later communism and Russia. This concept of the Pertubateur is still in use in contemporary French debate.

The same mechanism can be observed in the US policy towards China. This is well described by Elbridge Colby, as a binding strategy: the construction of a ring of US allies around China will deny military intervention by the latter. Economic trade agreements and military alliances go hand in hand in this line of thought. This quest for alliances is not a unique western matter, China is doing the same with engagements towards Thailand, Laos, Vietnam and Salomon islands. Also Russia, during the war in Ukraine has used its Pacific navy for naval diplomacy in the  Indian Ocean  and South China Sea, e.g. through conducting exercises with the Chinese Navy.

European naval diplomacy will be different than US naval diplomacy. Dutch naval diplomacy will need to be part of, and contribute to, Europe’s policy of open strategic autonomy. In 2021 Germany sent the frigate FGS Bayern to the Indo-Pacific for an independent seven-month deployment to underpin its value-based foreign policy and to support international law and the rules-based system. However, such  unilateral action was at the risk of unclear interpretation with counterproductive or limited utility. Naval diplomacy as an expression of international solidarity should be conducted by a group of international warships, of which the Dutch participation of warship Evertsen in the 2021 Indo-Pacific deployment of the US British Carrier Strike Group can be seen as an example that connected Europe and the Anglo Saxon world. Although limited in contribution, it did provide an opportunity to participate and thus influence this deployment.

Supporting European policies in the East

As analyzed by Van Willigen and Blarel, European signaling will be different and more ambiguous than American diplomacy. Nevertheless, adaptiveness and versatility of navies can enable Europe to display its global interests and commitments in a European way. Fear that such European involvement will further escalate, rather than stabilize, shouldn’t exist when such presence is recognizable as European and does not blend into Anglo Saxon structures.

Nonetheless, naval diplomacy can be counterproductive if it is handled poorly. In the 1960s the Dutch Government sent a task group including carrier Karel Doorman to New Guinea in an attempt to retain this last colony in the East Indies. The mission failed, and the main reason for this failure was a lack of international support. This example demonstrates that naval diplomacy, foreign policy and the creation of multilateral stability should all be synchronized. Navies can act as an enabler in this triangle. Without presence in the East, Europe cannot be influential in Asia.

By an exploration of three characteristics of sea power: versatility as an instrument to stabilize, mobility to move across different spheres and being an expression of coalition solidarity, it is concluded that locking up navies in European waters would underutilize the advantages sea power can offer. Obviously, during a crisis in Europe the fleet will likely be needed at home, but this should not preclude opportunities to use European warships to support European policies in the East. Nevertheless, considering that consensus exists that European armed forces, including naval capabilities need to be strengthened because US-support cannot be taken from granted, this article should not be read as neglecting security risks in Europe. Instead, it is argued that a sufficiently strong navy, capable to operate worldwide will both serve European interests far away and at home. History has taught that, occasionally, the US has a tendency to  isolationism. Europe cannot afford such an approach.

Header photo: Wikimedia Commons / UK MOD © Crown copyright 2021

Captain RNLN Henk Warnar is associate professor in Naval War Studies at the Netherlands Defence Academy in Breda.