In 2018, the US withdrew from the Iran nuclear deal and subsequently spent the next few years trying to renegotiate a new deal with the Iranians. This set off a period of Iran going back and forth on its position that continues to this day. The theories of some political scientists, such as the realist scholar Kenneth Waltz, suggest that going ahead to obtain nuclear weapons would only cause Iran to lose out in the long run in its security goals. Iran would eventually face what political scientists call a Security Dilemma, where its attempts to gain the upper hand in military power over its neighbours in a regional environment defined by insecurity and anarchy would merely spark a stronger response from them. Ironically, this would lead to an arms race that would in turn reduce its own security (D’Anieri, 2021). This outcome seems likely for an Iran which faces the might of EU and US economic sanctions, as well as its adversaries, Saudi Arabia and Israel, being economically stronger than it. 

Despite all this, Iran has not made a concerted effort to reach another nuclear deal, as negotiations have continuously been strained by unforgiving positions and rhetoric taken by Iran throughout the past few years. Its stance has oscillated between being seemingly committed and uncommitted to reach a deal (McBride, 2022). Although there might be a multitude of reasons, this partially points to a motivation to obtain nuclear weapons in spite of this Security Dilemma, suggesting that there are more significant factors at play that are influencing Iran’s stance. This essay argues that a primary factor is the fact that nuclear weapons are the ultimate weapon of psychological deterrence, and that irrespective of circumstance, obtaining one almost guarantees the survival of regimes from external powers.

The most intuitive reason for this is the fear of escalation into nuclear war, should a nuclear power decide to conduct aggressive military action against a smaller, nuclear-armed regime. The fear is that the regime would respond to an imminent national security threat by employing these weapons onto its opponent, inflicting unacceptable damage and millions of casualties. This is widely understood. However, there are several complexities to this idea which underscore just how effective nuclear weapons are at allowing nuclear-armed regimes to escape the Security Dilemma. 

Firstly, when other powers respond to a nuclear-armed regime by increasing their armaments, it does not necessarily decrease the security of that regime as posited by the Security Dilemma, because it does not decrease the degree of deterrence that regime has over these other powers with its nuclear weapons. (I am making two assumptions here: that there are differing levels or ‘degrees of deterrence’, and that the greater the degree of deterrence the regime’s nuclear weapons arsenal has over its adversaries, the greater the security to that regime.) This is because the deterrent effect afforded to the regime by nuclear weapons largely does not hinge on the number of weapons a country has. Even if another power has many more nuclear weapons than the regime does, the few weapons the regime has will still impose an unacceptable cost on them should it decide to attack them with its weapons. This is because it is difficult if not almost impossible to stomach even a small-scale nuclear attack.

Although a power like China under Mao might be willing to lose hundreds of millions of Chinese people to fight a nuclear war, the aggressive power would struggle to maintain cohesion even in the event of a small scale nuclear attack (Beinart, 2017). Nuclear weapons would be aimed at command and control centres and facilities such as capital cities, which would destroy government and institutional infrastructure. Even if the leadership could survive such an attack in underground bunkers, they would struggle to restore cohesion and control. In the wake of the atomic bombings of Hiroshima and Nagasaki, even firefighting and medical services were severely compromised, let alone every other function of government (Nagasaki National Peace Memorial, n.d.). Moreover, productive economic centres would be devastated, which would deal a major blow to the capacity and willingness of the nation to fight on. The destructive power of today’s nuclear weapons are measured in the kilo and megatons - thousands of times more powerful than the bombs used on Japan. A single weapon would easily be capable of completely destroying a large city. Therefore, this would pose an unacceptably high security risk to an outside power. Taking a policy action that risks provoking even a small nuclear response by a lightly-armed nuclear regime would result in catastrophic consequences for the outside power, no matter how many more nuclear weapons it has and no matter how many of them it might launch at that regime in response.

It is also almost impossible to defend against even a small-scale nuclear attack. Although today’s most advanced Anti-Ballistic Missile systems (ABMs), such as the Terminal High-Altitude Area Defence system (THAAD) have stated kill probabilities of up to 90%, this means a 10% chance of major destruction as stated earlier (Elleman et al., 2016). Moreover, there are many caveats to this number. Moreover, a large number of environmental and situational factors, such as submarine-launched nuclear ballistic missiles or decoy missiles, make it impossibly hard to ensure that even small attacks can be completely repelled (Elleman et al., 2016). For example, many nuclear states today employ ballistic missiles with Multiple-Independent Reentry Vehicle (MIRV) warheads, allowing a single missile to carry multiple real nuclear and decoy warheads, overwhelming ABMs attempts to intercept all of them. Therefore, possessing countermeasures and defences such as ABM systems do not do much to change the deterrence equation, since it only takes one missile to get through to deal unacceptable damage.

Therefore taken together, the idea that a regime pursuing nuclear weapons would be worse off in its security by the security dilemma is undermined. The regime’s adversaries responding by increasing their nuclear weapon stockpiles or creating countermeasures would not actually reduce the deterrence power of even just a few nuclear weapons it might have. It takes just one such weapon to get through an ABM net and to hit one major city in order to have an unacceptably devastating effect on any adversary.

The deterrent power of a small stockpile of nuclear weapons does not change even when considering tactical nuclear weapons. One might argue that the Security Dilemma applies in the context of tactical nuclear warfare, in which small, low-yield nuclear weapons are used on the battlefield, as this does not lead to any existential threat on an aggressor. The problem is that it is difficult to ensure that there is no escalation from tactical-level nuclear warfare into strategic-level nuclear warfare, which is the type of nuclear war mentioned earlier that targets cities with high-yield weapons (Jervis, 1979). The regime might respond to an aggressor's use of tactical weapons with its strategic weapons, thinking that that would scare the aggressor into submission. However, it is very difficult for an aggressor to ensure that the regime will not do this, as it is difficult to predict what is the precise point the regime will choose to escalate to the strategic level, nor to accurately deduce the regime’s strategy of nuclear employment. Intelligence gathering is never 100% accurate. In essence, the idea of uncontrolled escalation, that any slip in judgement or unforeseen changes to battlefield circumstances could trigger a strategic-level escalation, largely ensures that aggressors would be deterred even from tactical-level nuclear employment by the regime’s nuclear weapons.

One might argue that a regime’s nuclear weapons cannot deter an outside power’s use of grey-zone actions against the regime, such as attempts to covertly destabilise a regime. However, the fear that these actions could destabilise the regime until it becomes replaced by a more rogue actor, who might in turn employ nuclear weapons more erratically is a powerful one to deter outside powers from conducting such grey-zone actions. History has shown that many toppled regimes become more unstable entities, such as the rise of ISIS in Iraq or the Libyan civil war that erupted in the wake of dictator Muammar Gadaffi’s removal from power in 2011. The fact that the US pressured Ukraine in 1994 to return its nuclear weapons to Russia when it became an independent state after the fall of the Soviet Union, even though its government was not an authoritarian regime nor a security threat to the west at the time, underscores the power of this fear.

The main point I am trying to make is it takes just obtaining a small stockpile of nuclear weapons to go a long way toward ensuring deterrence and upending the calculations and strategic positions between states. How an adversary might respond with defences or an arms race to the regime obtaining a few nuclear weapons does not matter. Obtaining nuclear weapons does not lead to diminishing security posed by the security dilemma for a nuclear-armed regime as it does not decrease its deterrence power. It is little wonder that many commentators over the years have evoked the narrative that Iran looked at the demise of other similar dictatorships that did not possess a nuclear arsenal, such as Saddam Hussein’s Iraq or Muammar Gaddafi’s Libya after foreign military interventions and decided to pursue its own nuclear weapons in order not to end up like them, but instead end up like a nuclear-armed North Korea which has barely faced reprisals from the other nuclear powers for its belligerent actions and rhetoric.

Written by Wong Yee Fay

Edited by Vishnu Vardni