Realism in an Age of Uncertainty: Power, Adaptation, and Strategic Freedom of Action

Realism has returned to the center of strategic debate. The war in Ukraine, U.S.-China competition, the conflicts in the Middle East, and the progressive weakening of multilateral institutions all seem to confirm some of realism’s fundamental insights: the international system remains anarchic, states continue to worry about their security, power matters, and no great power can ultimately entrust its survival to the intentions of others.

Yet the return of power politics raises a further question. If realism continues to explain why states compete, can it still explain how they should compete in a system marked by growing complexity and uncertainty?

The question matters most when realist theory is used not only to interpret state behavior but also to anticipate the consequences of state action.

Contemporary wars reveal a paradox. We have access to unprecedented amounts of information, increasingly sophisticated intelligence capabilities, and computational tools able to process enormous volumes of data.

Yet analysts looking at essentially the same phenomena often arrive at profoundly different interpretations and predictions.

Realism and Uncertainty

It would be an oversimplification to argue that realism has ignored uncertainty from its origins. On the contrary, uncertainty belongs to realism’s intellectual genealogy. Classical realism, with Hans Morgenthau as one of its principal exponents, assigned a central role to prudence in political action. International politics could not be reduced to a scientific exercise in which known initial conditions produced predictable outcomes; decision-makers had to contend with the limits of knowledge, unintended consequences, misperceptions, and the impossibility of fully controlling the effects of their actions.

With Kenneth Waltz and structural realism, the problem changes in nature. The analysis is no longer dominated primarily by the fallibility of the decision-maker but by the anarchic structure of the international system. States must provide for their own security because no higher authority can guarantee it, and the distribution of capabilities shapes their behavior accordingly.

But this condition does not necessarily imply the indefinite accumulation of power. States seek above all security and survival; excessive increases in power can trigger counterbalancing by others and produce an outcome opposite to the one intended.

Defensive realism develops this insight further. Rather than a theory attributable to a single author, it is a body of thought that grew out of Waltz’s structural realism and was subsequently elaborated, from different angles, by scholars including Robert Jervis, Stephen Walt, Charles Glaser, and Stephen Van Evera.

Within this tradition, the security dilemma, threat perception, and the offense-defense relationship take on particular importance. These variables help explain why anarchy does not necessarily generate the same strategic behavior under all circumstances.

The security dilemma, in particular, shows how a decision that is perfectly rational from the perspective of one state can generate an equally rational response from another and produce an outcome that leaves both worse off. An increase in A’s security may reduce B’s perceived security. If B responds in an effort to restore it, A may read that response as confirmation of the original threat and adopt further countermeasures.

Each actor’s behavior thus becomes part of the conditions to which the other responds, pushing the system into a feedback dynamic. The rationality of an action, in other words, does not guarantee the rationality of its outcome.

Mearsheimer and the Paradox of Uncertainty

John Mearsheimer’s offensive realism takes the argument a step further. Great powers operate in an anarchic system, possess offensive military capabilities, cannot know with certainty the future intentions of other states, regard survival as their primary objective, and act rationally. From these conditions follows an important consequence: because no state can rule out the possibility that another great power may turn hostile in the future, the most reliable guarantee of survival is to increase its relative power. When circumstances permit, a great power will therefore seek opportunities to improve its position, with regional hegemony representing the most favorable condition for its security.

It is precisely here that a paradox emerges.

Uncertainty is a founding premise of offensive realism, yet it is then translated into a relatively predictable strategic response. The impossibility of knowing another state’s future intentions makes it rational to prepare for the worst case, which creates an incentive to seek greater relative power, on the logic that the more powerful a state is relative to its competitors, the greater its chances of survival should be.

The logic is internally compelling, but it assumes something that looks less certain in today’s strategic environment: that a sufficiently predictable relationship can be established among increased power, increased security, and improved strategic positioning.

It is precisely this relationship that needs to be reconsidered. What happens when an action undertaken to increase power changes the behavior of other actors and, through their responses, transforms the very conditions under which that power will subsequently have to be exercised?

When Power Changes the System

A state does not exercise power within a static environment. Every action changes an adversary’s behavior, influences allies, and shapes the perceptions through which other actors interpret the situation.

What distinguishes today’s environment is not necessarily greater instability than in the past, but the speed at which the effects of action propagate across increasingly interconnected systems.

Those consequences can extend from the military domain into technology, economics, industry, politics, and society, altering coalitions, dependencies, and even the political identities of the actors involved. A war launched to increase strategic depth can end up expanding the very alliance it was meant to keep at a distance. A coercive policy designed to extract a concession can push the adversary to develop capabilities that reduce the future effectiveness of that coercion. Technological superiority can create industrial dependencies that later become vulnerabilities. An alliance can dramatically increase the aggregate power of its members while simultaneously imposing new constraints on their freedom of action.

The problem, therefore, is not simply that other actors react.

It is that their reactions propagate across interdependent domains and progressively transform the system within which power must continue to be exercised.

When Uncertainty Comes From the System Itself

Realism has always assigned uncertainty a central role. That uncertainty concerns, first, what a state cannot fully know about other actors, their intentions, capabilities, perceptions, and future decisions. It is this strategic uncertainty that feeds the mistrust inherent in an anarchic system, in which no state can permanently entrust its security to the intentions of another.

Postwar Europe is a telling example. The American security guarantee dramatically enhanced European security, but Europe’s growing dependence on that guarantee progressively narrowed some of its autonomous options, making the continent’s security increasingly contingent on the long-term continuity of American capabilities, interests, and strategic commitment.

There is, however, a deeper condition. In some circumstances the problem is not simply that we do not know what another actor will do, or that we cannot assign reliable probabilities to events we have already identified. We may not even know all the relevant events that could occur, and so may be unable to construct a complete space of future possibilities. This is generally what is meant by radical uncertainty.

For strategy, though, it matters equally to understand where some of that uncertainty originates.

In complex adaptive systems, the future is hard to know not only because information is incomplete or unexpected events occur, but because some uncertainty arises from the operation of the system itself: actors take actions that provoke responses, and those responses progressively alter the conditions under which subsequent decisions must be made. A military decision can change other states’ threat perceptions and generate new alliances. An economic measure can encourage the construction of alternative supply chains. Technological superiority can push competitors toward asymmetric capabilities. A coercive policy can secure an immediate concession while simultaneously creating incentives to eliminate the vulnerability that made the coercion effective in the first place.

Action, in short, does not simply produce an outcome. It changes some of the conditions on which subsequent outcomes will depend.

We can describe this component of uncertainty, generated by the system’s own endogenous transformation, as systemic uncertainty. The term is not meant to introduce a new general category of uncertainty, but to isolate analytically the component that arises from the capacity of strategic interactions themselves to alter the system’s future conditions.

It is therefore neither an alternative to radical uncertainty nor a superior category to it. Radical uncertainty describes a condition in which we cannot fully identify all relevant future events or assign reliable probabilities to their occurrence; systemic uncertainty identifies one of the processes that helps produce that condition. The system changes, in part, as a consequence of the actions and reactions of the actors operating within it.

The distinction matters. In the traditional problem of strategic uncertainty, a state seeks to understand an adversary whose future intentions cannot be fully known. Under systemic uncertainty it confronts an additional problem: while acting on the basis of present conditions, the consequences of its own actions help change future conditions.

The ongoing confrontation between the United States and Iran illustrates the point. The exercise of American military superiority has produced not only an Iranian military response but also operational adaptation, changes in how the Strait of Hormuz is used as strategic leverage, effects on energy flows and the choices of regional actors, and new economic and political pressures. The system within which the United States and Iran continue to confront one another is therefore no longer exactly the system in which the initial decisions were made.

The space of possibilities should not, then, be imagined as a fixed set of scenarios among which the one that will ultimately materialize is merely hidden. Interaction can alter that space itself, generating constraints, opportunities, relationships, and capabilities that did not exist, at least not in the same configuration, when the initial decision was made. From this perspective, the future is not simply unknown; it is, in part, constructed through interaction.

This is precisely what complicates the traditional relationship between power and security.

If the exercise of power helps transform the system in which that power must subsequently be exercised, it is not enough to ask how much power a state can accumulate.

We must also ask what kind of system its exercise of power will help produce, what position the state will occupy in the system that emerges, and what options for action it will have preserved.

The Problem of Maximization

This distinction changes the meaning of power maximization itself. If the environment were sufficiently stable, increasing relative power could be a rational strategy for enhancing security and influence.

But in a complex adaptive system, second- and third-order effects also matter, consequences generated not directly by the initial action but by the reactions, adaptations, and subsequent interactions it sets in motion.

An increase in military power can strengthen deterrence, but it can also produce balancing: other states, perceiving a shift in the balance of power as a potential threat to their own security, may increase their military capabilities, strengthen existing alliances, or form new ones to counterbalance the rising power.

The result can be paradoxical, a state that has increased its absolute power may find itself in a relatively less favorable strategic position because of the reactions that increase has generated.

Similarly, acquiring territory may increase strategic depth while also raising the cost of defending and controlling it. Greater coercive capability may secure immediate concessions while accelerating the formation of opposing coalitions or encouraging other actors to reduce the vulnerabilities that coercion depended on. Greater technological specialization may increase efficiency and operational superiority while simultaneously creating dependencies and points of vulnerability that reduce overall resilience.

The point, then, is not to deny that greater power can produce greater security. It is to recognize that the strategic value of power cannot be measured independently of the reactions its accumulation and use generate within the system.

An important conclusion follows: maximizing present power does not necessarily maximize future strategic options.

From Power to Freedom of Action

None of this means that power has lost its centrality. On the contrary, power remains what makes many of a state’s options practically exercisable. A strategy that lacks the necessary capabilities may possess alternatives in theory without having the means to turn them into action.

The issue is instead how power should be assessed under conditions of uncertainty. Its strategic value depends not only on the ability to achieve a particular result today, but also on the ability to preserve freedom of action over time or a state’s capacity to retain strategically meaningful, practically exercisable options even after the conditions under which its original strategy was formulated have changed.

This does not mean keeping every possible alternative open, an impossible and often inefficient objective. It means avoiding decisions that create dependencies, rigidities, or hard-to-reverse commitments that excessively narrow future choices. Freedom of action therefore depends on power, but also on how that power is configured. Resources, alliances, industrial and technological capabilities, resilience, redundancy, and the ability to repurpose available instruments all help determine not only how much a state can do, but also how readily it can change what it is doing when conditions change.

The traditional question — how much power do I possess relative to my adversary? — must therefore be accompanied by another: what options for action will I retain after the exercise of that power has changed the behavior of others and the system in which we operate?

The difference is profound.

A strategy can achieve its immediate objective while simultaneously degrading the position from which subsequent crises will have to be confronted. It can win a war and worsen the broader competition. It can acquire territory and lose influence. It can create an adversary’s dependence and, through the coercive exploitation of that dependence, encourage the adversary to build alternatives. It can maximize a particular capability while reducing its own resilience.

Strategic rationality, therefore, cannot be judged solely by immediate results. It must also be judged by the position those results create over time and the options they leave available for what comes next.

From Prediction to Navigation

This conclusion also changes the relationship between analysis and strategy. Strategic planning traditionally begins by understanding the environment, forming an assessment of how it may evolve, building a plan consistent with that assessment, and then translating the plan into action. This logic remains necessary: no strategy can dispense with understanding context or forming hypotheses about the future.

But when the system’s endogenous transformation makes the conditions on which a forecast was built less stable, the assumption that a sufficiently accurate prediction can serve as a stable foundation for the entire strategy becomes increasingly fragile. The answer is not to abandon prediction, but to recognize its limits and, above all, not to make strategy dependent on the realization of a single expected future.

The ability to anticipate must therefore be paired with the ability to observe the system continuously, interpret signals of change, preserve alternative options, assess the effects of one’s own actions, and modify strategy when the initial conditions no longer hold. This is the shift from prediction to navigation.

Navigation does not mean proceeding without a destination, nor does it mean replacing strategy with improvisation. It means distinguishing the objective from the route: the strategic objective may remain relatively stable while the path required to reach it must be able to change in response to a shifting environment.

From this perspective, diversity, redundancy, modularity, experimentation, feedback, and reversibility should not automatically be treated as inefficiencies to be eliminated. They can be reserves of freedom of action, allowing states to change instruments, combinations, and pathways when the future they actually encounter diverges from the one their original planning assumed.

Strategy under uncertainty, in other words, does not abandon prediction.

It abandons dependence on prediction.

A Return to Prudence?

Paradoxically, this argument may bring us back to Morgenthau. The prudence of classical realism grew out of an awareness of the limits of knowledge and the need to assess not only the objectives of political action but also its possible consequences. Prudence was not simply caution, still less immobility. It required the ability to align ends, means, and circumstances while recognizing that control over the consequences of action would always remain limited.

In today’s environment, this insight can be reinterpreted in light of complexity and uncertainty. Prudence can also mean exercising power without prematurely foreclosing alternatives that may become necessary as conditions change.

The point is not to replace power with adaptation, a state incapable of exercising power does not become strategically stronger simply because it is flexible. Rather, adaptability should be understood as one of the qualities of power, because it shapes a state’s ability to reconfigure resources, instruments, and strategies when the environment develops in directions different from those anticipated.

Seen in this light, prudence means more than asking whether a state possesses the means to achieve an objective. It also requires asking what consequences the use of those means will generate, and what options will remain available once they have been used.

Realism in an Age of Uncertainty

Realism retains a strong capacity to explain fundamental features of international politics. Anarchy has not disappeared. Competition continues to characterize relations among great powers. Security remains a fundamental interest, and power continues to shape what states can and cannot do.

For precisely that reason, what needs to be reconsidered is not the centrality of power but how we assess its strategic value in a complex adaptive system. Power cannot be evaluated solely in terms of resources possessed, the balance of capabilities relative to adversaries, or the immediate ability to secure a desired outcome. It must also be evaluated in terms of the ability to preserve options as the system changes.

This does not refute realism or eliminate the logic of competition.

Rather, it suggests incorporating a temporal and adaptive dimension into the assessment of power. The issue is not simply how much power a state can accumulate, but what position that accumulation and the subsequent exercise of that power will help produce over time.

This leads to a proposition that modifies, without rejecting, the logic of maximization: under conditions of systemic uncertainty, strategic superiority does not necessarily depend on the ability to impose the desired outcome today, but also on the ability to preserve sufficient options for action after the consequences of today’s decisions have helped transform the system.

Strategic superiority, therefore, may not necessarily belong to the state that accumulates the most power, nor to the one that produces the most accurate forecast of the future. It may belong to the state that combines power, resilience, adaptability, and freedom of action more effectively than its competitors.

This means moving from a predominantly quantitative conception of power toward one that is also qualitative and temporal.

What matters is not only how much power a state possesses, but how that power is organized, how readily it can be reconfigured as conditions change, and what options for action it allows the state to preserve over time.

The decisive question of strategy, then, is not only: how much power do we possess today?

But also: what options will we still have tomorrow, after we have used it?