The character of warfare is undergoing a profound transformation. While the fundamental nature of war – competition, coercion and violence remains unchanged, the methods by which states pursue strategic advantage have evolved dramatically. Conventional military forces remain essential, but the decisive battles of the twenty-first century are increasingly fought beyond traditional frontlines. The new centre of gravity lies in the resilience of a nation’s Critical National Infrastructure (CNI). Energy grids, telecommunications networks, transport systems, financial institutions, water supplies and digital connectivity have become both strategic assets and prime targets. The future of conflict is increasingly focused on disrupting, degrading and manipulating the infrastructure that underpins modern societies.

Recent conflicts in the Middle East and Ukraine have demonstrated this shift. Military success is no longer measured solely by territorial gains but by the ability to paralyse an adversary’s essential services. Attacks on energy facilities, communications networks and logistics hubs aim not only to destroy physical assets but to undermine political legitimacy, economic stability and public confidence. Modern warfare has become multidimensional, combining kinetic strikes with cyber operations, electronic warfare and information campaigns to generate strategic effects far greater than the weapons themselves might suggest. Infrastructure has become both the battlefield and the weapon.

The war in Ukraine has reinforced this reality with exceptional clarity. Russia’s sustained campaign against Ukraine’s electricity generation, transmission networks and energy distribution systems has demonstrated the strategic value of targeting CNI. Missile and drone attacks have sought to deny electricity, heating and communications to civilian populations while constraining Ukraine’s military capability. These were not simply tactical operations but part of a broader strategy of societal attrition intended to erode resilience, impose economic costs and weaken national morale. Ukraine has also demonstrated the offensive potential of this approach, conducting strikes against Russian economic targets, including major retail infrastructure, bringing the effects of war directly to the civilian population and illustrating how infrastructure attacks can generate strategic pressure without territorial conquest.

For the United Kingdom, these developments demand serious reflection. Britain possesses one of the world’s most interconnected economies, supported by sophisticated digital networks and globally integrated supply chains. While these strengths generate prosperity, they also create strategic vulnerabilities. Russian intelligence services and state-sponsored cyber actors have repeatedly been linked to espionage, cyber intrusions and hostile activities directed against the UK and its allies. Such operations form part of a broader strategy of hybrid warfare, combining cyber-attacks, disinformation, economic coercion and intelligence activity to exploit vulnerabilities without crossing the threshold of conventional war. The objective is not immediate destruction but the gradual erosion of resilience and strategic advantage.

Geography no longer guarantees Britain’s security. An adversary need not deploy forces across the English Channel when malicious cyber activity, disinformation campaigns or attacks on undersea communications cables can create significant national disruption. Britain’s offshore energy infrastructure, submarine telecommunications networks, financial systems and maritime trade routes are all critical national assets whose protection is now inseparable from national defence. Safeguarding CNI should therefore be viewed not as a peripheral homeland security issue but as a core military responsibility.

Within this context, the Royal Navy assumes renewed strategic importance. Maritime power has always underpinned Britain’s prosperity, but its role now extends well beyond traditional sea control. The Navy has become a key enabler of joint operations across the maritime, land, air, cyber and space domains while protecting the infrastructure on which national resilience depends. Undersea communications cables, offshore wind farms, energy pipelines and global shipping routes collectively form an extensive maritime battlespace that demands continuous surveillance, credible deterrence and effective defence.

Meeting this challenge requires sustained investment and modernisation. Additional surface combatants and submarines remain essential, but equal emphasis must be placed on autonomous systems, artificial intelligence, cyber resilience, seabed surveillance, anti-submarine warfare and integrated command-and-control systems capable of responding rapidly to hybrid threats. Maritime security increasingly depends on the ability to detect, attribute and counter hostile activity beneath the surface as much as above it.

This investment must be understood as a genuinely imperative, The Royal Navy, British Army and Royal Air Force must continue developing an integrated force capable of protecting national infrastructure across every operational domain. Shared intelligence, resilient communications and interoperable technologies will define future military effectiveness. Defending CNI also requires close coordination between the armed forces, government departments, intelligence agencies, industry and international allies, recognising that national resilience has itself become a strategic capability. The Navy’s offensive capability today is also vital for hard diplomacy, deploying offensive strike groups when needed, and the ability to secure supply chains at short notice. 

The future battlefield is no longer confined to trenches or fleets. It encompasses power stations, fibre-optic cables, ports, satellites, financial systems and digital networks upon which modern societies depend. Nations capable of defending these interconnected systems will possess a decisive strategic advantage, while those that cannot risk paralysis before conventional combat even begins. The future of war is already here. Success in the coming decades will depend not simply on the size of armed forces but on the ability to protect – and, when necessary, contest – the critical national infrastructure that underpins military power, economic prosperity and national sovereignty. Investing in the navy therefore must be a priority. 

* Edward Marsh is a Lib Dem member in Merton.