Concerns about the Iranian nuclear program are at their height today. Some observers wonder if Tehran has deliberately dragged out negotiations on reviving the Joint Comprehensive Plan of Action (JCPOA) to expand its status as a nuclear weapons threshold state. The Iranians could dare to irritate Washington, counting on the United States’ reluctance to engage militarily against them. In this scenario, the American and Israeli threat of military intervention only aims to push Iran to give up its demands and renew the 2015 deal—they are not ready to intervene. Due to the possibility of military escalation and the expected effects on the global energy market, the warnings coming from Washington and Tel Aviv could be no more than empty threats.

Others who believe the Iranians are eager to reach an agreement are worried that Tehran would be able to build nuclear weapons once the deal sunsets, or even while it is in force. The latter is feasible due to limits on the International Atomic Energy Agency’s ability to monitor Iran’s production of uranium enrichment centrifuges. These limits raised suspicions that Iran could (ab)use the temporary inability of the IAEA in order to move the centrifuges to clandestine sites. That being the case, Teheran could secretly enrich fissile material and ultimately build nuclear weapons.

Considering the pros and cons, however, the rationality of going nuclear is questionable. It is unlikely that Iran would get away with it as Israel, India, and Pakistan have. The world would react to the Iranian acquisition of nuclear weapons as it did in the case of North Korea. What’s more, Tehran would not only fail to achieve any gains but would jeopardize its ability to realize its vital foreign policy goals, risking the very survival of the Islamic Republic.

Prestige and the desire for a status symbol could be among the motives for obtaining nuclear weapons. For Charles de Gaulle, the nuclearization of France was not only a security issue but also something to influence the French self-image as a great power. The acquisition of nuclear weapons could boost the perception of Iran as a regional power to a degree, but it has no profound effect today as in the 1960s. Although it is difficult to determine the precise impact of this political symbolism, it can hardly be worth the risks. Moreover, in light of strengthening the non-proliferation regime, going nuclear would tarnish Tehran’s image globally and cement the perception that Iran is a pariah state, as shown in the example of North Korea.

It is worth noting that nuclear weapons are not seen by experts as appropriate for offensive political goals in modern times. Iran's paramount foreign policy goals are to export the Islamic revolution throughout the region and support actors with similar ideologies. However, nuclear weapons can hardly contribute to Iran's ability to promote an Islamic awakening or back its allies. One could say that the Iranian nuclear umbrella could be a way to do so. But in fact, the weapons would be ineffective in protecting regional actors such as Hezbollah or Syrian president Bashar al-Assad against the threats they could face. Neither Israel nor the United States would be deterred from their actions against those foes if Iran had nuclear weapons.

Providing material aid is a key component of Tehran’s support to friendly actors, and going nuclear would reduce its ability to do so. The expenses of maintenance and modernization of the nuclear arsenal and means of delivery, although not insignificant, are less important here. Rather than the cost of keeping nuclear weapons, what matters more is the economic retaliation that would follow Iranian nuclearization. Despite recent claims that Russia is helping Iran bolster its nuclear program, Moscow has no interest in seeing Tehran acquire nuclear weapons. The same is true for China, which would prefer an interim solution that could present the United States with a crisis every so often. For that reason, by going nuclear, Tehran would risk broader sanctions. Consequently, it would burden Iran’s already crippled economy and decrease its ability to support its allies in the Levant and Yemen.

The defensive function of nuclear weapons is yet another feature to consider. To decisionmakers in Tehran, state security is regime safety. Their rule, disputed ever since the Islamic Republic emerged, is particularly challenged today. Nationwide protests are shaking the system as the reign of Ayatollah Khamenei is nearing its end, inciting uncertainty and intrigue around the expected power transition. Nevertheless, nuclear weapons cannot help Iranian political structures maintain their power. They could not keep the Soviet Union together nor prevent the South African black majority from ending the apartheid regime. Similarly, the ultimate weapons would not help the Ayatollahs and the Islamic Revolutionary Guard Corps (IRGC) preserve their rule.

Concerning external threats, nuclear weapons would enhance Iran's security to some extent, so deterrence is the most credible motive for acquiring them. But is this additional security necessary, and what are the risks of achieving it?

Saudi Arabia is averse to conflict with Iran. Tehran has more than enough conventional weapons to inflict unacceptable damage to the energy infrastructure and economy of Saudi Arabia. It is highly improbable that the Saudis would accept the risks of initiating a war with Iran. On the other hand, geography limits large-scale Israeli attacks on Iranian territory. Sure, the Israelis target Iran with cyber-attacks and assassinations now and then—but nuclear weapons cannot help against asymmetric threats coming from Tel Aviv.

From Tehran's perspective, the most acute threat to deter is the one coming from the United States. But Washington is reluctant to take the risks of war with Iran only to influence their usual behavior or change the regime. Since vast amounts of energy flow through the Strait of Hormuz, a conflict with Iran could be as harmful to the global economy as the war in Ukraine, not to mention their combined effect. Besides, considering both the defender's capabilities and the dangers posed to American ambitions in other parts of the world, a war with Iran would be a more difficult challenge for the United States than those fought in Afghanistan and Iraq. If Washington has not attacked Iran before, it is unlikely to do so now, since it is pivoting to Asia and trying to cope with the China challenge. Therefore, Iranian deterrence already works.

The only thing that is likely to push the United States to face the dangers of war is its intention to prevent Tehran from weaponizing its nuclear program. Stopping another rogue state from acquiring the ultimate weapons could be worth the risks of escalation. After all, Washington has pledged to use all means available to prevent Tehran from making a nuclear bomb.

Considering Iran's likely retaliation against American troops and allies in the region, the conflict could prove costly for the United States, but it would certainly hit Tehran harder. The war could end the Iranian nuclear program and devastate the economy. But more importantly, the conflict would provide fertile ground for regime change. Paradoxically, an attempt to prevent regime change by building the bomb could lead to its realization. An American attack would probably not follow an Iranian statement that it will make the bomb, but rather intelligence signaling that Tehran has crossed the red line. As intelligence can fail and mislead, an ill-informed attack might occur in times of mistrust.

The tragic nature of the Iranian nuclear issue goes beyond the possibility of premature war. The very roots of the current problem could be ill-conceived, as Iran most likely never needed more security. This example illustrates the malign spiral caused by the security dilemma, where a desire for more security could increase the level of threat, destroy prosperity, or even endanger the state's survival. But even in a scenario of successful weaponization that would not provoke a military attack by the United States, nuclear weapons would jeopardize Iran's capabilities to realize its interests in the region. Iran would not increase its security, the regime would not enhance its stability, and its ability to pursue its regional policy would decrease.

All in all, are the Iranians building a bomb behind the world’s back? Although their rationality and threat perception are biased and affected by negative historical experiences with the United States, Tehran can hardly ignore the high cost and risks of going nuclear. Indeed, while the Iranians continue to boost their nuclear program, they are cautious not to provoke a military response by America. Iran has not passed the threshold of 60 percent uranium enrichment and avoids employing its full capacities. Therefore, the Iranian breakout time has been fairly stable for some time.

The continuous advancement of the Iranian nuclear program below the red lines is a sort of pressure on Washington to make further concessions in the talks on the revival of the JCPOA. As with the unrealistic demands for guarantees that the next administration will not unilaterally pull the United States out of the deal again, the Iranians are trying to get more than they did under the 2015 deal. Although they are playing a dangerous game, whereby the worst-case scenario may easily prevail, the Iranians would likely be happy to see at least a small gesture from the United States to signal a political and moral victory over Washington. Since a minor back down is less costly than the undesired options, Washington should at least consider some alternatives to Iranian demands.