Nuclear War: Strategies and Concepts in the Post-War Era

Nuclear weapons are unique among the tools of war: their primary purpose is not to be used, but to ensure they never have to be. Since the bombings of Hiroshima and Nagasaki in 1945, no nuclear weapon has been fired in anger, yet these weapons have shaped global politics for eight decades. The reason lies not in the bombs themselves but in the strategies built around them. Nuclear war strategy is really the study of how nations use the threat of catastrophic violence to influence one another’s behaviour. This post unpacks the core concepts that define this field: deterrence, brinkmanship, coercive diplomacy, and compellence, along with the arms control efforts and defensive programmes that grew out of them.

Why nuclear strategy is different from conventional strategy 🔗

In conventional warfare, military force is meant to be applied. Armies clash, territory changes hands, and victory is measured in battles won. Nuclear weapons broke this logic entirely. A full nuclear exchange between two well-armed states would not produce a winner. It would produce mutual ruin. This single fact transformed the purpose of these weapons from fighting wars to preventing them.

The American economist and strategist Thomas Schelling, who later won the Nobel Prize, captured this shift in his 1966 work Arms and Influence. He argued that violence is most purposive and most successful when it is threatened rather than actually used. In other words, the value of a nuclear arsenal lies in the bargaining power it gives a state, not in its battlefield application. Schelling described force as part of an ongoing negotiation between adversaries, a kind of diplomacy conducted through the manipulation of fear. Understanding this idea is essential to grasping every concept that follows.

Deterrence: preventing war through the threat of destruction 🔗

Deterrence is the foundation of nuclear strategy. At its simplest, it means discouraging an adversary from attacking by convincing them that the costs of doing so would far outweigh any possible gains. A state with credible nuclear weapons signals to its rivals: attack me, and you will suffer unacceptable damage in return.

For deterrence to work, three conditions must be met. The threatened state needs the capability to inflict severe damage, the credibility to make the threat believable, and the ability to communicate that threat clearly to the opponent. If any of these fails, deterrence weakens.

Mutual assured destruction 🔗

During the Cold War, deterrence evolved into its most famous form: mutual assured destruction, or MAD. The idea was that if both the United States and the Soviet Union could destroy each other even after absorbing a first strike, neither would dare to attack. The phrase is often traced to U.S. Defense Secretary Robert McNamara, who in the mid-1960s proposed a doctrine of “assured destruction” that expressly targeted Soviet population centres, arguing that the guarantee of mutual annihilation would serve as an effective deterrent to both sides.

MAD rests on a concept called second-strike capability: the ability to retaliate even after suffering a surprise nuclear attack. This is why nuclear powers spread their weapons across land, air, and sea, hiding submarines in the oceans so that no enemy could destroy all of them at once. Game theorists describe this situation as a form of Nash equilibrium, in which neither side has any incentive to strike first or to disarm. Though no one has ever tested whether MAD truly works, it is widely credited with preventing direct war between the superpowers for over four decades.

India’s approach to deterrence 🔗

India offers a distinct model of nuclear deterrence. Its doctrine is based on the principle of credible minimum deterrence, which means maintaining just enough survivable nuclear force to deter adversaries without entering a costly arms race. A cornerstone of this policy is No First Use (NFU): India pledges not to use nuclear weapons unless first attacked with them. The official doctrine, released in January 2003, states that any nuclear retaliation by India would be massive and designed to inflict unacceptable damage, with authority resting solely with the civilian-led Nuclear Command Authority. This restraint-based posture differs from MAD by emphasising sufficiency and survivability rather than parity in numbers.

Brinkmanship: walking up to the edge 🔗

If deterrence is about preventing action, brinkmanship is about applying pressure. It involves deliberately escalating a confrontation toward the edge of war to force the other side to back down. The gamble is that your opponent will blink first rather than risk catastrophe.

Schelling famously defined brinkmanship as the manipulation of the shared risk of war. The essence of such a crisis, he noted, is that neither side remains in full control of events, which creates a genuine danger of miscalculation and escalation. This loss of control is not a flaw in the strategy; it is the strategy. By introducing real uncertainty, a state makes its threats more credible, because even an “irrational” outcome becomes possible.

Scholars have illustrated this with Schelling’s image of two mountaineers chained together at the edge of a cliff. Neither wants to fall, but one can pressure the other by stepping closer to the edge, exploiting the shared risk that an accidental slip could doom them both. The 1962 Cuban Missile Crisis is the classic real-world example, where the United States and the Soviet Union brought the world dangerously close to nuclear war before stepping back.

The limits of brinkmanship 🔗

Brinkmanship is effective only when threats are credible, and credibility requires a willingness to actually follow through. The strategy carries enormous danger because the very mechanism that makes it work, the risk of losing control, can produce the catastrophe both sides are trying to avoid. A misread signal, a technical malfunction, or a panicked decision could turn a bluff into a disaster.

Coercive diplomacy and compellence: forcing a change in behaviour 🔗

While deterrence aims to stop an opponent from doing something, compellence aims to make them actively do something, or stop something they have already started. Schelling coined the term “compellence” precisely because the word “deterrence” failed to capture this active dimension of coercion.

The difference comes down to who moves first. Deterrence is a passive threat that places the initiative on the opponent: it simply warns them not to act. Compellence, by contrast, shifts the initiative to the coercer, who demands that the target change course. Schelling also noted that compellence requires punishment to be administered until the other side acts, rather than as a one-time response. The pressure continues until the demand is met.

How coercive diplomacy works 🔗

Compellence is popularly known as coercive diplomacy, the use of threats and limited force to achieve political objectives without resorting to all-out war. According to the framework developed from Schelling’s work, it typically follows a three-pronged structure: a specific demand is made to the adversary, a sense of urgency or a deadline to comply is communicated, and a credible threat of punishment is issued if they refuse.

Crucially, coercive diplomacy relies on the threat or limited use of force rather than its full application. The goal is to influence the opponent’s calculations, leaving them an exit that allows compliance. Schelling captured this with the disturbing logic of hostage-taking: the power to hurt is most effective when held in reserve, because any act that destroys the hostage reduces its own coercive value. Once you have used up your leverage, you have nothing left to bargain with.

Why compellence is harder than deterrence 🔗

Strategists generally agree that compellence is more difficult to achieve than deterrence. Asking an opponent to actively change course, often in a visible way that may humiliate them, is far harder than persuading them to refrain from acting. Compellent threats are also costly when they fail: they can stiffen the target’s resistance and damage the coercer’s reputation in the eyes of other states watching the outcome. This is one reason why coercive diplomacy has a mixed historical record.

Arms control: managing the danger 🔗

The recognition that nuclear war could never truly be “won” pushed states toward a parallel strategy: limiting the weapons themselves through negotiation. Arms control does not aim to eliminate nuclear weapons overnight but to reduce the risk of war, slow expensive arms races, and build predictability between rivals.

The cornerstone of this effort is the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), which entered into force in 1970. The treaty rests on three pillars: preventing the spread of nuclear weapons, promoting peaceful uses of nuclear energy, and pursuing eventual disarmament. With 191 states parties, the United Nations describes it as the most widely adhered to arms limitation agreement in history. Notably, India, Pakistan, Israel, and South Sudan remain outside it, with India objecting to its discriminatory division of the world into nuclear “haves” and “have-nots.”

The superpowers also negotiated bilateral limits. The Strategic Arms Limitation Talks (SALT I) and the Anti-Ballistic Missile (ABM) Treaty were both signed in 1972, capping the number of missiles and restricting defensive systems. Later agreements such as the Strategic Arms Reduction Treaties (START) went further, requiring the actual destruction of delivery vehicles under intrusive verification. Together these treaties show that strategy and diplomacy are two sides of the same coin.

The Strategic Defense Initiative and the defence puzzle 🔗

One of the most ambitious and controversial chapters in nuclear strategy was the Strategic Defense Initiative (SDI), proposed by U.S. President Ronald Reagan in a televised address on March 23, 1983. SDI envisioned a network of space- and ground-based systems, including lasers and interceptors, that could shoot down incoming Soviet missiles before they reached American soil. Because parts of it would be based in space, the press quickly nicknamed it “Star Wars.”

SDI was significant because it directly challenged the logic of MAD. Reagan was driven by a deep aversion to nuclear weapons and hoped to render them “impotent and obsolete” by building an effective shield. But this exposed a paradox at the heart of nuclear strategy. If one side could reliably defend itself against retaliation, the balance of mutual vulnerability that kept the peace would collapse, and the other side might feel pressured to strike first or build more weapons to overwhelm the shield.

For this reason, the Soviet Union viewed SDI as deeply destabilising, and disagreements over it complicated arms control talks throughout the 1980s. The programme also faced severe technical doubts, with many scientists arguing that a perfect missile shield was simply beyond the reach of the technology of the time. SDI was never fully deployed, but it left a lasting mark on debates about whether defence and deterrence can coexist.

Bringing the concepts together 🔗

These strategies are not isolated theories but interlocking parts of a single logic. Deterrence sets the baseline by making aggression too costly to contemplate. Compellence and coercive diplomacy extend that logic into active pressure, using threats to change an adversary’s behaviour. Brinkmanship is the high-risk tool that makes such threats credible by deliberately raising the stakes. And arms control works in the opposite direction, trying to manage the dangers all these strategies create.

What unites them is a striking conclusion: in the nuclear age, the goal of strategy is to avoid the very thing it prepares for. Despite enormous advances in weapons technology, from multiple-warhead missiles to ambitious defensive programmes, the central aim has remained the same: to ensure these weapons are never used. The history of nuclear strategy is, in this sense, the history of a war that everyone is determined not to fight.

What do you think? Does India’s doctrine of credible minimum deterrence with No First Use offer a more responsible model than the Cold War logic of mutual assured destruction? And if a perfect missile defence system ever became possible, would it make the world safer, or would it dangerously upset the fragile balance that has kept nuclear peace?

References

1. https://www.cfr.org/articles/primer-military-force
2. https://www.britannica.com/topic/mutual-assured-destruction
3. https://en.wikipedia.org/wiki/Mutually_assured_destruction
4. https://carnegieendowment.org/research/2016/06/indias-nuclear-doctrine-debate?lang=en
5. https://en.wikipedia.org/wiki/Brinkmanship
6. https://direct.mit.edu/isec/article/47/3/9/114669/The-Psychology-of-Nuclear-Brinkmanship
7. https://en.wikipedia.org/wiki/Compellence
8. https://www.goodreads.com/book/show/205482307-arms-and-influence
9. https://tnsr.org/2020/02/coercion-theory-a-basic-introduction-for-practitioners/
10. https://disarmament.unoda.org/en/our-work/weapons-mass-destruction/nuclear-weapons/treaty-non-proliferation-nuclear-weapons
11. https://ahf.nuclearmuseum.org/ahf/history/non-proliferation-limitation-and-reduction/
12. https://www.britannica.com/topic/Strategic-Defense-Initiative
13. https://www.history.com/articles/reagan-star-wars-sdi-missile-defense