National Security in Realist Perspective: Priorities and Controversies

When governments decide how to spend money, sign treaties, or build alliances, one concern usually overrides everything else: staying safe. For the realist school of international relations, this is not an accident. Realists argue that national security is the supreme national interest – the foundation on which prosperity, diplomacy, and even ideals are built. Without security, nothing else a state wants becomes possible. This post explains why realists place security at the top, who the major thinkers are, and why a sharp debate within realism itself shapes how we understand war, peace, and cooperation today.

Why security sits at the top of the realist agenda 🔗

Realism is one of the oldest and most influential ways of understanding world politics. It views international relations as a competition among self-interested states operating in a system with no central authority above them. This condition is called anarchy – not chaos, but simply the absence of a world government that can enforce rules or protect anyone.

Because no global police force exists, each state must look after itself. Scholars call this principle self-help. According to the realist tradition, the insecurity of states is the central problem of international politics, and states must provide their own security because no other actor reliably will. From this starting point, security becomes the precondition for everything else. A state that cannot guarantee its survival cannot pursue economic growth, cultural influence, or moral goals. Survival comes first; all other interests follow.

This is why realists treat national security not as one policy area among many, but as the bedrock interest. Protecting sovereignty, defending territorial integrity, and deterring external threats are the non-negotiable tasks of any government.

The thinkers who built the realist case 🔗

Realist ideas stretch back thousands of years, but a handful of thinkers gave the tradition its modern shape.

Machiavelli and the survival of the state 🔗

The Italian thinker Niccolò Machiavelli is one of the earliest voices in this tradition. In The Prince (1532), he argued that a leader’s primary concern is to promote national security. For Machiavelli, a ruler had to be alert to both internal and external threats and willing to use force when necessary to guarantee the state’s survival. He famously suggested leaders need the qualities of both the lion (strength) and the fox (cunning). Crucially, he argued that rulers follow an “ethics of responsibility” rather than ordinary morality – they should be good when they can, but must act ruthlessly when survival is at stake.

Morgenthau and the national interest 🔗

Hans Morgenthau, often called the father of classical realism, gave the theory its twentieth-century framework. He argued that national interest is the prime motivation behind foreign policy, and that survival is the fundamental national interest. For Morgenthau, states are led by human beings who are, by nature, power-seeking. Since states are run by people, states too pursue power. In his view, the reliable tools for protecting the national interest are not international law or moral appeals but balance of power, diplomacy, and deterrence.

Morgenthau also distinguished between core national interests, which are fundamental and unchanging, and variable interests, which shift with circumstances. This explains why countries show continuity in their foreign policy on existential questions while adjusting on lesser matters.

Waltz and the structure of the system 🔗

Kenneth Waltz shifted the focus from human nature to the structure of the international system. In his 1979 book Theory of International Politics, he launched neo-realism (also called structural realism). Rather than blaming conflict on flawed human nature, Waltz argued that the anarchic structure itself pushes states toward competition. His position on security is famously direct: in anarchy, security is the highest end, and only once survival is assured can states safely pursue other goals like profit, tranquility, or influence.

The security dilemma: when defence looks like aggression 🔗

One of realism’s most important contributions is the concept of the security dilemma. First named by John Herz in 1950, it describes a frustrating trap. When one state increases its military capabilities to feel safer, neighbouring states perceive this as a threat and respond by building up their own forces. The result can be an arms race and rising tension – even when no state actually wants war.

The security dilemma is a core assumption of defensive realism. According to Waltz, because the world has no common government and is anarchic, states distrust the intentions of others and constantly try to maximise their own security. The dilemma explains how purely security-seeking states with no hostile intentions can still end up in dangerous confrontation. Scholars such as Robert Jervis later refined this idea, showing that the intensity of the dilemma depends on whether weapons and strategies favour offence or defence.

The relationship between India and Pakistan offers a clear regional illustration. Each side’s defensive build-up – including nuclear weapons – has often been read by the other as a threat, feeding a cycle of suspicion that is hard to break even during periods of dialogue.

The great debate: defensive versus offensive realism 🔗

Realists agree that security is paramount, but they disagree sharply on how much power a state needs to feel secure. This disagreement splits the tradition into two camps and has major consequences for how we view the prospects of peace.

Defensive realism: enough is enough 🔗

Defensive realists, following Waltz, argue that states are not naturally aggressive. The anarchic system actually encourages defensive and moderate policies rather than reckless expansion. In this view, states are security maximisers, not power maximisers. Once a state has enough power to be safe, it becomes content and stops chasing more.

There is a logic behind this restraint. If a state grabs too much power, other states grow alarmed and band together to balance against it. Waltz argued that this balancing behaviour should discourage states from pursuing hegemony, since a bid for dominance simply provokes an encircling alliance that ultimately undermines the would-be hegemon’s own security. The first concern of states, in Waltz’s words, is to maintain their position in the system – not to maximise power.

Offensive realism: never enough 🔗

John Mearsheimer challenged this conclusion in his 2001 book The Tragedy of Great Power Politics. He starts from the same assumptions as Waltz – anarchy, uncertainty about others’ intentions, the priority of survival – but reaches the opposite conclusion. Mearsheimer argues that the international system requires states to maximise their offensive power and keep rivals from gaining at their expense. A state’s ultimate goal, he claims, is to become the most powerful actor in its region – the hegemon.

The reasoning is rooted in uncertainty. Because a state can never be sure of another state’s true intentions today, let alone tomorrow, no level of power ever feels truly safe. Mearsheimer therefore argues that power preponderance is the best safeguard for survival. States are condemned to perpetual competition, and only regional hegemony offers genuine security. He calls this grim logic the “tragedy” of great power politics: even states that only want safety are forced into conflict to achieve it.

Why this debate matters 🔗

This is not merely an academic quarrel. The defensive-offensive split shapes how each camp views the chances for international peace and cooperation. Defensive realists leave room for restraint and stability, since satisfied states have no reason to keep fighting. Offensive realists are far more pessimistic, predicting endless rivalry among great powers. The debate is highly relevant to current questions, such as how to interpret the rise of China – whether Beijing will settle for regional security or push aggressively for dominance.

Realism, national interest, and the limits of cooperation 🔗

Across both camps, realists tend to be sceptical about deep, lasting cooperation between states. Neo-realists in particular argue that states care about relative gains rather than absolute gains – meaning a state worries not just about whether it benefits from a deal, but whether a rival benefits more. This concern with relative position breeds caution about treaties, trade arrangements, and international institutions, which realists view as useful only when they serve the national interest.

This explains a recurring pattern in world affairs. Powerful states often help create international organisations such as the United Nations, yet reserve the right to bypass them when core security interests are at stake. For realists, this is entirely predictable. Institutions are instruments of state interest, not substitutes for self-help.

The realist emphasis on self-reliance also shows up in concrete policy. The drive to build a domestic defence industry, for example, reflects the realist belief that national interest is rooted in the pursuit of power and security, pushing states to reduce dependence on external suppliers and strengthen their own capabilities against future threats. India’s long-standing pursuit of strategic autonomy and indigenous defence production fits this logic well.

Strengths and criticisms of the realist view 🔗

Realism endures because it explains a great deal of state behaviour that more optimistic theories struggle with – recurring wars, arms races, alliance shifts, and the priority states place on military strength. Its focus on power and survival offers a sober, practical lens for analysing a dangerous world.

Yet the approach has critics. Some argue that the security dilemma assumes threats are always genuine, when in fact fear may sometimes be based on misperception rather than real hostile intent. Liberals and constructivists also point out that realism underestimates the role of cooperation, shared norms, economic interdependence, and the way national interests can be socially constructed and can change over time. Realism’s heavy focus on the state can also overlook non-state actors, transnational threats, and human security concerns that cross borders.

Even so, the realist framework remains a starting point for serious analysis of national security. Understanding why states prioritise survival, and how the defensive-offensive debate plays out, gives us powerful tools for interpreting everything from regional rivalries to great-power competition.

What do you think? If states genuinely seek only security, why do arms races and wars still happen so often – is it human nature, the structure of the system, or simple misperception? And looking at India’s own neighbourhood, do you see state behaviour fitting more closely with the defensive realist logic of restraint or the offensive realist logic of seeking dominance?

References

1. https://en.wikipedia.org/wiki/Realism_(international_relations)
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6. https://en.wikipedia.org/wiki/Security_dilemma
7. https://en.wikipedia.org/wiki/Defensive_realism
8. https://www.e-ir.info/2014/03/06/john-mearsheimers-theory-of-offensive-realism-and-the-rise-of-china/
9. https://www.cambridge.org/core/journals/politics-and-the-life-sciences/article/evolution-of-offensive-realism/56B778004187F70B8E59609BE7FEE7A4
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12. https://www.researchgate.net/publication/297753634_Hans_Morgenthau_and_the_National_Interest
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