Limited nuclear war is back in the strategic debate. It is a risky concept that raises questions about deterrence, escalation, and global stability.
Summary
Limited nuclear war is no longer a mere theoretical exercise inherited from the Cold War. In an international context marked by multipolarity, the erosion of arms control frameworks, and the emergence of low-yield nuclear weapons, several states are reevaluating the possibility of limited nuclear use, targeting specific political objectives without descending into all-out war. Inspired by Clausewitz’s concepts of limited warfare, this approach is based on the idea that restricted use, controlled geographically and quantitatively, could restore deterrence or force an adversary to negotiate. But this hypothesis faces a central problem: uncertainty. In the fog of conflict, it remains extremely difficult to distinguish a limited signal from a prelude to widespread escalation. The risks of misinterpretation, escalation, and the collapse of deterrence remain high. The temptation exists, but the gamble is dangerous.
The concept of limited war inherited from Clausewitz
Reflection on limited war did not begin in the nuclear age. Carl von Clausewitz defined war as the continuation of politics by other means. This formula, often quoted but rarely explored in depth, implies that armed violence is never an end in itself. It is a tool in the service of political objectives. A limited war is therefore characterized by the deliberate restraint of the means employed and by the proportionality between the military effort and the political stakes.
Historically, many conflicts have followed this logic. The Korean and Vietnam wars, although deadly, never mobilized the full military capabilities of the major powers involved. The limits were geographical, the intensity of the strikes, and the ultimate objectives. The total destruction of the adversary was not sought. When the cost exceeded the political interest, the war ended.
This conceptual framework has long been considered incompatible with nuclear weapons. The prevailing idea during the Cold War was simple: nuclear weapons, due to their destructive power, made any limitation illusory. Once the threshold was crossed, escalation became almost automatic. It is precisely this certainty that formed the basis of classic nuclear deterrence.
Conventional nuclear deterrence and its structural limitations
Nuclear deterrence is based on one central principle: the certainty of unacceptable retaliation. The doctrine of mutually assured destruction (MAD) was based on massive arsenals capable of wiping out entire societies. In the 1980s, the United States and the Soviet Union each had more than 30,000 nuclear warheads. The mere survival of a few hundred was enough to inflict catastrophic losses.
This logic effectively prevented a direct confrontation between the major powers. But it had one major weakness: the absence of credible gradation. Either nothing was done, or annihilation was risked. For some American strategists, such as Bernard Brodie, this rigidity made deterrence ill-suited to limited crises or peripheral conflicts.
Starting in the 1960s, the RAND Corporation and the Pentagon explored alternative scenarios. They sought options that would signal determination without triggering an apocalypse. Most of these exercises ended in uncontrolled escalation. The conclusion was harsh: even limited use could be perceived as existential by the adversary.
These conclusions relegated limited nuclear war to the background for several decades. Crisis management then relied on conventional conflicts, which were considered more controllable, while retaining nuclear weapons as a last resort.
The resurgence of the concept of limited nuclear war
Over the past fifteen years or so, the nature of the debate has changed. Several converging developments explain this return.
First, the transformation of the international system. The world is no longer bipolar. The United States, Russia, China, but also India, Pakistan, North Korea, and Israel have nuclear capabilities. The balance of power is more fragmented. The red lines are less clear.
Second, technological developments. Low-yield nuclear weapons are changing perceptions of the nuclear threshold. Some warheads have yields of less than 10 kilotons, compared to 15 kilotons for Hiroshima. By way of comparison, a 5-kiloton strike on an isolated military target could destroy a few square kilometers without wiping out an entire city.
Finally, the erosion of arms control treaties plays a major role. The end of the INF Treaty, uncertainties surrounding New START, and widespread modernization of arsenals reinforce the temptation to adopt more flexible doctrines.
In this context, some states consider that limited, clearly defined nuclear use could achieve a specific political objective: deterring conventional advances, breaking a military deadlock, or restoring the credibility of deterrence.
The operational definition of limited nuclear war
There is no universal definition of limited nuclear war. To clarify the debate, several criteria are generally used.
First, the type of weapons used. These would be low-yield warheads, often less than 10 or 15 kilotons. These weapons are designed for tactical or operational use.
Next, the volume. The number of strikes would be limited, sometimes to just one or two explosions. The objective would be to send a signal, not to destroy the adversary.
Geography is a third criterion. Strikes would be confined to a limited area: a theater of operations, a military base, or a maritime zone.
Finally, the political objectives would be explicitly limited. The aim would not be to overthrow a regime or destroy a state, but to influence a specific decision.
On paper, this framework seems coherent. In practice, it is based on a fragile assumption: the adversary’s ability to understand the intention and respond in a proportionate manner.
The risks of escalation and the problem of perception
The heart of the problem lies in perception. In the fog of conflict, how can a limited strike be distinguished from the first step toward a massive attack? Early warning systems, automated doctrines, and very short decision-making times accentuate this risk.
Even a low-yield nuclear strike produces signals identical to those of a larger attack: radar detection, satellite alerts, immediate political pressure. The adversary often has only a few minutes to decide. In this context, the temptation to overreact is strong.
Cold War war games showed that most scenarios involving limited nuclear war quickly escalated. Each side feared being outmaneuvered if it did not strike harder immediately.
Added to this is the human factor. Leaders may misinterpret their adversaries’ intentions, underestimate their risk tolerance, or overestimate their ability to control the situation. A supposedly rational doctrine can be shattered by a miscalculation.
Strategic implications for modern deterrence
The reemergence of limited nuclear war is profoundly changing nuclear deterrence. It introduces a dangerous gray area between non-use and mass destruction.
On the one hand, some believe that the absence of intermediate options weakens deterrence. If a state does not believe in the credibility of a total strategic response, it may be tempted to act below the nuclear threshold. Offering limited options would therefore strengthen deterrence.
On the other hand, this flexibility could trivialize nuclear weapons. By lowering the threshold for use, the risk of it being crossed one day is automatically increased. Nuclear weapons would shift from being a tool for non-use to an instrument of crisis management, which is a major change.
The figures illustrate this paradox. Today, there are approximately 12,000 nuclear warheads in the world, nearly 90% of which are held by the United States and Russia. Even a limited conflict would involve only a tiny fraction of these arsenals. But history shows that conflicts do not always follow the expected scenarios.
Long-term political and security consequences
If limited nuclear war became an accepted option, the consequences would be severe.
Politically, the norm of non-use of nuclear weapons would be weakened. Non-nuclear states could reconsider their position and seek to acquire similar capabilities, believing that the weapon has once again become “usable.”
Militarily, doctrines would harden. Conventional forces would become increasingly intertwined with nuclear forces, increasing the risk of confusion on the battlefield.
Finally, on a human and environmental level, even a limited strike would have lasting effects. A 5-kiloton explosion in a military zone would cause thousands of immediate casualties, radioactive contamination, and irreversible political consequences.
What the current debate really reveals
The rise of the debate on limited nuclear war does not indicate that states wish to use nuclear weapons. Above all, it reveals a growing concern about a less predictable world, where the frameworks inherited from the Cold War are no longer sufficient.
The temptation to believe in perfect control is strong. But strategic history shows that war often escapes those who think they can control it. When it comes to nuclear weapons, this illusion could cost much more than theoretical calculations suggest.
Sources
Clausewitz, On War
Bernard Brodie, The Absolute Weapon
RAND Corporation, studies on nuclear escalation (1960s–1980s)
SIPRI Yearbook 2024
U.S. Department of Defense, Nuclear Posture Review
Recent academic publications on deterrence and nuclear multipolarity
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