Has Our Definition of an Attack Become Obsolete?

Why hybrid warfare is forcing governments and businesses to rethink strategic risk

Introduction

Every generation inherits its own understanding of war.

For much of the twentieth century that understanding was remarkably consistent. Wars began when armies crossed borders, planes bombed cities or navies blockaded ports. An attack was visible, destructive, and difficult to misunderstand. Those conflicts shaped international law, military doctrine and political decision making because they reflected the strategic realities of their time.

That understanding still influences us today.

Ask someone what an attack looks like and they are likely to describe Ukraine. They picture missiles striking apartment buildings, drones hunting tanks, artillery reducing towns to rubble and soldiers fighting over territory. Those images dominate our television screens because they are the clearest expression of conventional war. They are also entirely consistent with the definition of conflict that most of us have inherited.

Yet history has a habit of quietly changing the assumptions that once seemed obvious.

Over the past few years, governments have investigated cyber operations against critical infrastructure, damage to undersea communications cables, GPS interference affecting civilian aviation, ransomware attacks on essential services, economic coercion, disinformation campaigns and increasingly persistent activity at sea below the threshold of armed conflict.[1][2][3] Each incident has generally been treated as a separate problem requiring a separate response. That is understandable. Different technologies, different jurisdictions and different government agencies naturally lead to different investigations.

The question this briefing asks is whether those investigations are also obscuring a larger strategic picture.

This is not an argument that every cyberattack should be regarded as an act of war or that every disruption to critical infrastructure is the work of a hostile state. The evidence does not support such conclusions. The argument is narrower but potentially much more significant. If states are increasingly able to influence political decisions, economic activity and public confidence without relying primarily on conventional military force, are we still recognising attacks in the way they are most likely to occur?

The answer has implications extending well beyond defence. It influences the way governments assess national resilience, the way businesses understand strategic exposure and the way boards think about risk. Before those implications can be explored, however, it is necessary to examine something most of us rarely stop to consider.

What, exactly, has changed?

The World Changed. Our Thinking Didn't

For most of modern history, the goal of war was clear. Military force was used to seize territory, destroy an opponent's armed forces or compel political leaders to accept terms they would otherwise reject. Success was measured by visible outcomes that could be seen on a map or a battlefield. As a result, governments naturally developed legal frameworks, military doctrine, and national security institutions around the expectation that attacks would also be visible.

That expectation made sense because the industrial age rewarded concentration. Armies concentrated people, equipment, and firepower. Cities concentrated industry. Ports concentrated trade. Destroying those concentrations produced immediate strategic effects, and military capability became the primary means of achieving them.

The twenty first century has introduced a different reality.

Modern societies no longer rely solely on physical infrastructure. They rely on highly connected systems that exchange information, energy, finance, and goods continuously across national borders. Electricity powers communications. Communications enable banking. Banking supports trade. Trade depends on transport, logistics and digital networks working with extraordinary precision every hour of every day. The more efficient these systems have become, the more interconnected they have become.

That interconnection has transformed the relationship between disruption and strategic effect.

A century ago, interrupting a nation's economy required destroying the infrastructure that supported it. Today, disruption does not always depend upon physical destruction. Interfering with communications, interrupting logistics, undermining confidence in financial systems or delaying the movement of goods can produce consequences that spread far beyond the original point of disruption. The aim is no longer necessarily to destroy the system. Increasingly, it is to influence the decisions of the people who depend upon it.

That distinction changes the way strategic competition should be viewed.

If the desired outcome is to influence political judgement, commercial behaviour, or public confidence, then the question is no longer simply whether military force has been used. It becomes whether a series of unrelated actions is collectively producing the same strategic effect that military force once looked to achieve.

This is not a replacement for conventional warfare. Ukraine proves that military power is still central to international security. Rather, it reflects an expansion in the methods available to states looking to achieve strategic advantage. Military force now sits alongside cyber operations, economic measures, information campaigns, legal pressure, and other forms of influence that can be applied individually or in combination depending on the goal being pursued.

This is why many of the events dominating today's headlines can appear disconnected while still contributing to the same strategic picture. They are usually reported according to the technology involved, the country affected or the government agency responsible for the response. Much less attention is given to the possibility that they may be different expressions of the same underlying trend.

Understanding that trend begins with recognising that the nature of strategic competition has evolved.

The question is whether our definition of an attack has evolved with it.

Looking at Familiar Events Through a Different Lens

Once we begin looking for strategic effect rather than simply the method used to achieve it, several recent events appear in a different light.

The widespread blackout across Spain and Portugal in April 2025 gives a useful example. Investigators concluded that the outage resulted from a cascading technical failure rather than hostile action.[4] That finding was important, but it was not the only lesson. Within hours, transport networks slowed, electronic payments became unreliable, businesses activated contingency plans and millions of people experienced how quickly modern society depends on systems that normally run unnoticed in the background. The incident was not an attack. It did, however, show the type of disruption an attacker might look to create deliberately.

The same observation applies to fuel distribution. The ransomware attack against Colonial Pipeline in the United States did not destroy pipelines, storage facilities, or fuel terminals.[5] Instead, it disrupted confidence in a system that supplied almost half the refined fuel used along the American east coast. Panic buying spread rapidly, emergency declarations were issued and shortages developed despite most of the physical infrastructure being still intact. The strategic consequences extended well beyond the original cyber intrusion.

The least understood example lies beneath the oceans. Almost all intercontinental internet traffic passes through fibre optic cables resting on the seabed.[6] Every international financial transaction, cloud service, government communication, and commercial data exchange depends upon this network working reliably. Recent incidents involving damaged undersea communications cables around Taiwan and in the Baltic Sea have therefore attracted increasing attention from governments, not simply because cables were damaged, but because of the strategic uncertainty such incidents create.[7][8] Was the damage accidental? Was it negligence? Was it deliberate? While those questions are being investigated, governments, businesses and markets are already responding to the consequences.

Reports of GPS interference across parts of Northern Europe reveal a similar pattern.[9][10] Most people associate satellite navigation with finding directions while driving. In reality, exact positioning and timing support civil aviation, maritime navigation, logistics, emergency services, and significant parts of the global financial system. Disrupting those signals does not need to bring planes down or stop ships moving to produce strategic effects. Delays, uncertainty, and reduced confidence may be sufficient to influence behaviour long before more visible consequences appear.

None of these events should automatically be grouped together, and none should be presented as evidence of a single coordinated campaign without supporting intelligence. That would be speculative and inconsistent with the evidence. Collectively, however, they illustrate something much broader. Modern societies have developed new forms of dependence, and with those dependencies come new opportunities for strategic pressure.

This is where the discussion begins to move beyond individual incidents.

If multiple forms of pressure are capable of influencing political decisions, economic activity and public confidence without relying on conventional military force, then perhaps we should spend less time asking whether each event resembles an attack and more time asking whether they are producing the kinds of strategic effects that attacks have always been intended to achieve.

The answer to that question leads directly to the concept that increasingly shapes modern strategic competition.

Hybrid warfare.

Hybrid Warfare Did Not Change the Objective. It Changed the Method

The goal of strategic competition has changed remarkably little throughout history. States have always looked to influence the decisions of other states, protect their own interests, and shape the international environment to their advantage. What has changed is the range of tools available to achieve those aims.

For much of the twentieth century, military power was the principal instrument through which strategic effects were created. Economic sanctions existed, intelligence operations were common and propaganda was widely employed, but these activities supported conventional military campaigns rather than working as strategic campaigns in their own right.

That distinction is becoming increasingly blurred.

The term hybrid warfare has emerged to describe the deliberate integration of military and non military instruments of national power to achieve strategic objectives without relying exclusively on conventional military force.[11][12] Cyber operations, economic coercion, legal pressure, information campaigns, intelligence activity, maritime operations and military capability are no longer viewed as separate lines of effort. Increasingly, they are planned and employed together, allowing each to reinforce the effects of the others.

The importance of hybrid warfare does not lie in the individual tools themselves. Cyber operations have existed for decades. Economic coercion is centuries old. Intelligence operations are as old as organised states, while propaganda has influenced conflicts throughout recorded history. None of these capabilities is new. The innovation lies in their deliberate integration and the ability to apply sustained strategic pressure without at once crossing the threshold that traditionally triggered a conventional military response.

Russia's activities across Europe provide one illustration of this approach. Alongside its invasion of Ukraine, European governments have investigated allegations of cyber operations, sabotage, GPS interference, influence campaigns and activity directed against critical infrastructure.[13][14] China has adopted a different approach across the Indo Pacific, combining military pressure, coast guard operations, legal claims, economic measures and persistent activity around Taiwan and the South China Sea to reshape the strategic environment without initiating full scale conflict.[15][16] The methods differ, but the strategic logic is remarkably similar. Rather than relying upon one decisive action, pressure is applied continuously across multiple domains, gradually influencing political judgement, commercial behaviour, and public confidence.

It would be misleading, however, to suggest that this approach is limited to Russia or China. The United States has long integrated military capability with intelligence operations, financial sanctions, cyber activities, and diplomatic pressure in pursuit of national goals. Israel, Iran, North Korea and other states employ different combinations reflecting their own strategic priorities. The methods vary according to national capability. The underlying principle does not.

This is why hybrid warfare should not be viewed as a separate category of conflict existing somewhere between peace and war. It is better understood as an evolution in the way states compete. Conventional military force is still an essential instrument of national power, but it increasingly works alongside a much broader range of tools that can influence an opponent long before the first missile is launched or the first soldier crosses a border.

Once viewed through that lens, the central argument of this briefing becomes clearer.

The defining characteristic of an attack is no longer necessarily the weapon that delivers it.

Increasingly, it is the strategic effect it is designed to produce.

That is a subtle change in language.

It is potentially a profound change in the way governments, businesses and societies understand strategic competition.

The Greatest Challenge Is Not Detection. It Is Decision Making

If modern strategic competition increasingly relies on combinations of military and nonmilitary pressure, the greatest challenge is not necessarily recognising individual incidents. It is deciding when those incidents collectively stand for something more significant.

Democratic societies are deliberately designed to move cautiously when confronted with serious accusations against another state. Evidence is gathered before blame is assigned. Intelligence is assessed before conclusions are reached. Governments seek legal authority before acting, while political leaders weigh the consequences of every response. These processes are fundamental to the rule of law and should not be viewed as weaknesses. They are among the reasons democratic nations stay resilient over time.

The difficulty is that modern strategic competition often unfolds within the time created by those safeguards.

Consider the questions governments now ask following every major disruptive event. Was the incident accidental or deliberate? Was it criminal activity or state sponsored? If a foreign government was involved, can that involvement be proved publicly without compromising intelligence sources? If responsibility can be shown, what response is proportionate? Should the response be diplomatic, economic, legal, cyber, or military? Every one of these questions is legitimate. Everyone needs time.

Meanwhile, the effects continue to accumulate.

Businesses begin reviewing supply chains. Investors reassess risk. Insurance premiums rise. Governments divert funding towards resilience programs. Infrastructure operators strengthen security. Public confidence shifts in response to uncertainty rather than certainty. Long before investigators reach their final conclusions, organisations have already begun changing their behaviour.

This is one of the characteristics that makes hybrid warfare so effective. It does not require governments to make poor decisions. It simply requires them to spend time reaching the correct ones while strategic pressure continues to build.

That distinction deserves greater attention because it changes the way success is measured. Conventional military campaigns traditionally looked to destroy capability or seize territory. Modern strategic competition increasingly looks to influence decisions. If political leaders delay investment, businesses redesign supply chains, governments redirect resources or alliances adjust their posture in response to sustained pressure, meaningful strategic effects may already have been achieved without a conventional military engagement ever occurring.

History suggests that major strategic shifts are rarely recognised while they are unfolding. Looking back, patterns often appear obvious. Living through them is more difficult. Individual incidents rarely announce that they form part of a larger campaign. They occur months apart, involve different technologies, affect different sectors, and are investigated by different organisations. Only with time does the broader pattern begin to appear.

That is why the central question posed by this briefing deserves closer attention.

If attacks are increasingly designed to influence decisions rather than simply destroy infrastructure, at what point do individual incidents become part of a strategic campaign?

There is no universally accepted answer.

Ignoring the question, however, is becoming increasingly difficult.

Why This Is No Longer Just a Defence Conversation

Once strategic competition is viewed through this lens, it becomes clear that responsibility no longer rests solely with defence ministries or intelligence agencies.

Much of the infrastructure that underpins national resilience is owned, operated or supported by the private sector. Electricity providers, telecommunications companies, ports, financial institutions, cloud service providers, logistics networks, transport operators, and advanced manufacturers all contribute to the functioning of modern society. Most do not think of themselves as participants in national security. Increasingly, they are.

That does not mean businesses should prepare for war.

It does mean they should understand that strategic competition now reaches well beyond military bases and government departments. The systems that support everyday commerce have become part of the environment in which states compete. Recognising that reality is no longer simply a defence issue.