Will Tehran Make a Dash for the Bomb?

With other components of its defense strategy in tatters, attention turns to Iran’s nuclear threshold capability.

By Sina Azodi

Iran’s national security doctrine is rooted in the painful legacy of the 1980-88 Iran-Iraq War. That conflict was marked by Iran’s international isolation, Iraq’s use of chemical weapons against Iranian troops and cities, and devastating shortages of military supplies. These experiences laid the groundwork for Iran’s “forward defense” strategy, built around three pillars: ballistic missiles and drones; support for regional nonstate actors; and a threshold nuclear capability. Each element of this strategy is designed to address vulnerabilities exposed during that war. However, the Israel-Hamas war has demonstrated the vulnerability of this strategy.

Recent Israeli operations against Iranian proxies, attacks within Iran’s own borders, and growing domestic calls to rethink its nuclear stance have presented Tehran with critical choices about the nuclear program’s strategic role. In recent months, two of the three pillars of Iran’s forward defense approach have been weakened in the face of Israelis’ demonstrable escalation dominance. Now the nuclear program is the only intact pillar, but the situation puts Tehran in a bind: Should it decide to cross the nuclear threshold, it could trigger a war with the United States and Israel.

Ballistic missiles have constituted the backbone of Iran’s national defense capability. Reliance on ballistic missiles finds its roots in the Iran-Iraq War, when Iranian cities were subjected to Iraq’s widespread use of missiles. “Tehran was burning every night under [Iraq’s] missiles. … We didn’t have missiles—we had nothing to defend ourselves with,” Iran’s supreme leader, Ayatollah Ali Khamenei, observed in 2018 about the war. That experience led Iranians to invest heavily in expanding missile production capacity, ultimately developing the largest ballistic missile arsenal in the region, with a variety of short-range and medium-range missiles—especially important in the absence of a modern air force capable of projecting Iran’s power in the region.

This year, Israel has in effect destroyed Iran’s most advanced air defense systems received from Russia in 2016. Following the Hamas attack on Israel on Oct. 7, 2023, and the subsequent outbreak of the Gaza conflict, Iran launched hundreds of ballistic and cruise missiles at Israeli targets in two separate attacks. While the first attack in April was largely defeated, the second missile attack on Oct. 1 was far more effective, with several ballistic missiles successfully bypassing Israel’s layered missile defense system, hitting the Nevatim air base.

Israel’s Oct. 26 response to Iran’s attack was far more effective than its previous response on April 19, which destroyed an S-300 radar at Isfahan’s 8th Tactical Air Base. The recent strikes marked the largest attack on the Iranian territory since the Iran-Iraq War. Reports indicate that the Israeli Air Force, using Iraqi airspace, launched attacks against missile production facilities and S-300 air defenses that protected critical oil and petrochemical refineries, as well as systems guarding a large gas field in Iran. These attacks have left Iran’s critical infrastructure extremely vulnerable to future strikes. As an unnamed Iranian source familiar with the country’s air defenses highlighted to me, “Iran’s air space is wide open like a highway.”

The October attack, which killed at least four Iranian army personnel, was initially played down by Iranian officials. However, the rhetoric slowly began to change, with senior Iranian officials vowing that Iran will “use all available tools to deliver a definite and effective response.” Iran now faces a difficult choice: It must carefully weigh the risks of retaliating against Israel against the possibility of it escalating into a broader and potentially devastating conflict.

Iran’s strategic isolation and lack of regional allies have profoundly shaped its national defense doctrine.

Addressing Iran’s loneliness in the region, President Masoud Pezeshkian said in September, “I am the president of a country that has repeatedly faced threats, wars, and occupations. No one has ever come to our aid, and our declarations of neutrality have been ignored.” In the absence of powerful state allies, Iran has turned to nonstate actors to project its power and conduct proxy warfare beyond its borders to defend the homeland.

These proxy forces, which form the second pillar of Iran’s national defense, are intended to limit the operational freedom of its regional adversaries and impose costs on Iran’s adversaries. In February, Amir Saeid Iravani, Iran’s envoy to the United Nations, compared Tehran’s relationship with what he called “resistance groups” to the NATO alliance. Essentially, these proxies bolster Iran’s security by providing an asymmetrical deterrent against the superior conventional forces of Saudi Arabia and Israel. However, growing pressure on its so-called Axis of Resistance forces has put Iran in a difficult position.

Iran now faces a critical choice: to back its allies, risking direct confrontation with Israel—a scenario referred to as chain-ganging—or to remain on the sidelines, potentially leaving its regional partners to fend for themselves. However, this would be contrary to the primary purpose of these forces—that is, to keep Iran out of a fight.

The assassination of Hamas political leader Ismail Haniyeh in Tehran along with the subsequent pager attacks and deaths of Hezbollah leader Hassan Nasrallah and, most recently, Haniyeh’s successor, Yahya Sinwar, have deprived these forces of some of their most experienced leaders. Additionally, Israeli operations in southern Lebanon have severely weakened Hezbollah, which functions as Iran’s queen on the regional geopolitical chessboard. Reports indicate that Hezbollah’s military, which defeated Israel in the 2006 war, has been severely degraded, though not destroyed.

Should Iran abandon its allies, it risks damaging its credibility abroad, with the effect of a potentially deteriorating security environment for itself. This may explain why, on Oct. 4, Khamenei, in a rare move, delivered the Friday sermon, pledging in Arabic continued support for the Axis of Resistance and reaffirming Iran’s commitment to the Palestinian cause. Either scenario is risky for Iran.

In response to these external developments, since early 2024 Iranian officials have shifted their discourse around the issue of nuclear weaponization. In February, Ali Akbar Salehi, the former head of Iran’s Atomic Energy Organization, likened Iran’s nuclear capability to assembling a car: “Imagine what a car needs—it requires a chassis, an engine, a steering wheel, a gearbox. You’re asking if we’ve made the gearbox; I say yes. Have we made the engine? Yes, but each component has its own function.” While this analogy underscores Iran’s technical readiness, previously taboo discussions about weaponization have become more explicit amid changing regional dynamics.

In October, 39 Iranian parliament members sent a letter to the Supreme National Security Council urging a reassessment of Iran’s defense doctrine regarding nuclear weapons. Adding to the escalating rhetoric, Kamal Kharazi, a former foreign minister and current advisor to Khamenei, warned that Iran’s nuclear stance could shift. “We now have the technical capabilities necessary to produce nuclear weapons. …

Only the supreme leader’s fatwa [against nuclear weapons] currently prohibits it,” he cautioned in early November. “If the survival of Iran comes under serious threat, we reserve the right to reconsider.” The current debate over Iran’s defense posture may genuinely stem from heightened security concerns amid regional threats, but it could also be a strategic ploy by Iranians to pressure the United States into restraining Israel’s aggressive actions. After all, Iranian Foreign Minister Seyed Abbas Araghch reiterated last week that Iran does not seek nuclear weapons.

Crossing the nuclear threshold would, in theory, give Iran the ultimate tool of deterrence, enhancing its regional influence. It could further enable Iran to match Israel’s nuclear arsenal in the region. This path is fraught with danger, though, as it risks provoking a potential conflict with the United States and Israel. Iran’s nuclear breakout time is currently estimated at one to two weeks, but if Tehran opts to dash for a bomb, it would likely need several months to a year to produce a usable nuclear weapon. During this period of vulnerability, Iran would be highly exposed to preventive strikes, particularly from the United States or Israel.

Several U.S. presidents, both Democratic and Republican, have stated that the use of the military to prevent Iran from obtaining nuclear weapons is on the table. Given Iran’s past intelligence lapses, any covert attempt to rapidly develop a bomb would likely be detected, prompting swift military intervention. In essence, any covert attempt at weaponization could be seen as an open invitation for foreign intervention, which could dissuade Iran from fully crossing the nuclear finish line. This scenario mirrors the decision Iran made in 2003, when fears of a U.S. invasion prompted it to halt its clandestine nuclear activities.

Iran is currently facing a predicament over its most prized national achievement: nuclear threshold status. While domestic pressure to develop a nuclear weapon is ostensibly growing, this move remains unlikely due to the considerable risks associated with weaponization. Furthermore, while Hezbollah’s leadership has been decapitated and its military strength has been weakened, it is not nearly close to a collapse. In the absence of a nuclear agreement to limit its program, the most plausible scenario is that Iran will continue edging closer to nuclear capability without fully crossing the threshold. This approach allows Iran to avoid preventive strikes while reducing the time required to assemble a weapon if an existential threat emerges, as only an acute security threat would likely push Iran to take the final step toward nuclear weapons. Such a crisis would include an attack on Iran’s nuclear infrastructure or the total collapse of Hezbollah.

Sina Azodi, a professorial lecturer of international affairs at the George Washington University’s Elliott School of International Affairs specializing in Iran’s nuclear program and national security.