The Evolving Role of Nuclear Rhetoric in Iran’s Strategic Calculus

In April 2025, Ali Larijani, a trusted advisor to Iran’s Supreme Leader Ali Khamenei and former Secretary of the Supreme National Security Council, declared on Iranian State TV that Iran “was not moving towards nuclear weapons”, but warned that if Western powers acted irresponsibly on the issue, Iran “would be forced” to reconsider.¹ This statement came in response to U.S. President Donald Trump’s threat to bomb Iran if negotiations over its nuclear program failed.

This direct reference to nuclear weapons by a senior Iranian official, marks a notable evolution in Iran’s official rhetoric regarding its nuclear program.² While the leadership continues to describe its nuclear program as peaceful, an increasing number of public statements from politicians, think tankers, and military officers now hint at a shift toward deterrence-driven signaling.

This rhetorical evolution did not emerge in a vacuum. Although there were occasional statements between 2018 – the year the United States withdrew from the JCPOA – and 2023 (as explored in this memo), a significant uptick has occurred since early 2024. This coincides with the deterioration of the regional security environment because of the Gaza War, which included two direct Israeli attacks on Iranian territory, in April and October 2024.The “twelve-day war” in June 2025, marked by Israeli and American strikes on Iranian nuclear and military facilities, further reinforced this trend and underscored the failure of “conventional deterrence”.³

In parallel, rhetoric from the European signatories of the JCPOA – France, Germany and the UK – as well as from the United States (especially after Donald Trump’s return to power) has grown increasingly confrontational. Western diplomatic postures, in alignment with U.S. policy, have also hardened and may have contributed to Iran’s shifting threat perception, thereby increasing the risk of miscalculation.

This memo argues that Iran’s evolving nuclear rhetoric should not be dismissed as mere posturing. It reflects a deeper strategic recalibration in response to the erosion of its conventional deterrence, heightened regional insecurity, and the perceived failure of the international non-proliferation regime. The rhetorical shift is both a signal to adversaries and a form of performative deterrence that mirrors escalation observed elsewhere, notably in nuclear-armed states.

The Iranian nuclear program: what do we know?

According to the latest IAEA report, published late May 2025, thus before the Israeli and U.S. strikes, Iran currently holds over seven tons of uranium enriched to various levels, including approximately 400kg enriched up to 60%. This stockpile would suffice to produce several nuclear explosive devices, even without reaching the 25kg of uranium enriched to 90%, which the IAEA defines as a “significant quantity”.⁴ However, and despite some gaps in the continuity of monitoring, both the annual U.S. intelligence community report and statements by the IAEA Director General affirm that Iran has not taken any technical steps toward weaponization. As Rafael Grossi summarized, “They have all the pieces”, but ultimately, the decision lies with the Supreme Leader.⁵

Ayatollah Khamenei has never publicly deviated from his long-standing opposition to nuclear weapons. He often dismisses the idea of Iran pursuing a nuclear bomb as a “Western lie” used to justify illegitimate sanctions against the country, and he frames his stance as grounded in Islamic principles. He is widely reported to have issued a fatwa declaring nuclear and other weapons of mass destruction as haram (forbidden). At the same time, he emphasizes the technical capabilities of Iranian scientists: “If it were not for this Islamic foundation and we wanted to build a nuclear weapon, we would have done so, and the enemies know they wouldn’t be able to stop us”, he stated during a visit to a nuclear industry exhibition in June 2023.⁶

Iran’s claim to a peaceful nuclear program is also often reiterated in numerous public letters and speeches by its representatives at the United Nations. In June 2024, this position was endorsed by two of Iran’s closest political and economic allies, China and Russia, in a joint letter to the UN Security Council.⁷ It was reaffirmed multiple times after the events of June 2025, when Iran described itself as the victim of “nuclear apartheid”: a non-nuclear weapons state whose nuclear facilities, officially dedicated for peaceful purposes, were targeted by two nuclear-armed states.⁸

Overall, it appears that, for now, the costs of pursuing a nuclear weapon – on the financial, technical, and strategic levels – still outweigh the potential benefits in the eyes of the Supreme Leader. However, the looming question of succession, as he is now 86 years old, complicates the picture. It remains unclear whether his religious stance against nuclear weapons will outlast him. While Khamenei remains the final arbiter of strategic decisions, the growing prominence of divergent voices within the regime, particularly in Parliament and the IRGC, suggests an increasingly pluralistic internal discourse that may persist beyond his leadership. Additionally, the June 2025 attacks on Iran’s nuclear infrastructure may also increase the appeal of weaponization and incentivize greater concealment in order to prevent future strikes.

Changing Iranian discourses: the quest for a renewed deterrence

Iran’s status as a “threshold state” –being able to develop a nuclear weapon within a few years and leveraging this capacity as a bargaining tool – has long been implied by Iranian officials. In August 2022, the head of the Atomic Energy Organization of Iran stated that the country had the capability to produce nuclear weapons, but that the political decision had not been taken yet.⁹ This posture was widely understood as part of a broader deterrence strategy built on three pillars: nuclear latency, a growing missile arsenal capable of striking neighboring countries with conventional warheads,¹⁰ and the “Resistance Axis” of allied militias intended to confront Iran’s adversaries across the region to deter direct attacks on Iran’s core interests.¹¹

Since October 2023, however, there has been a growing consensus within the Iranian strategic community that this triad has weakened. Repeated Israeli strikes on Hezbollah, including the September 2024 targeting killing of Hassan Nasrallah, have eroded the group’s capacity to exert pressure on Israel. Once the crown jewel of the Axis, Hezbollah is now seen as less capable of deterring Tel Aviv from carrying direct operations against Iran, as its ability to retaliate has been severely diminished. The fall of Bashar al-Assad in Syria dealt another major blow to Iran, severing its access to the Mediterranean and disrupting the critical land corridor used to transfer supplies to Lebanon and Gaza. Meanwhile, Operation Sea Guardian – launched by the United States and United Kingdom in late 2024 to target Houthi rebels in Yemen – followed by a renewed U.S. airstrike campaign under Donald Trump in Spring 2025, has further blunted the Axis’ capacity to provide Iran with strategic depth and a buffer zone against direct threats.¹²

The deterrent effect of Iran’s important missile arsenal was also dented by the two missile exchanges with Israel in April and October 2024.¹³ Notably, Israel’s strike in October broke a long-standing taboo against open, airborne attacks on Iranian soil – marking a shift from previous actions that were more covert, such as the 2021 assassination of nuclear scientist Mohsen Fakhrizadeh by Israeli intelligence. This feeling of failure was further reinforced during the early days of the twelve-day war in 2025, when the Israeli air campaign exposed the vulnerability of Iranian air and missile defenses in protecting key facilities, especially when compared to the high interception rate of the Israeli missile defense against successive waves of Iranian ballistic missiles.

This crisis in deterrence has been acknowledged by Iranian officials, with some explicitly linking it to the potential need for nuclear weapons. Following Israel’s strike on Iran’s consulate in Damascus, the head of the Strategic Council on Foreign Relations declared: “We have no decision to produce a nuclear bomb, but if Iran’s existence is threatened, we will be forced to change our nuclear doctrine”.¹⁴ Iran’s sharper rhetoric must therefore be understood against the backdrop of a shrinking deterrent toolkit. As conventional assets lose credibility – proxies weakened, and the missile taboo broken – Tehran appears to rely more heavily on rhetorical escalation to reassert deterrence.

Even before the Israeli and U.S. strikes, pressure on the Supreme Leader was growing. In October 2024, 39 members of parliament wrote to the Supreme National Security Council, announcing they would ask Khamenei, “if he deems appropriate”, to revise the fatwa on nuclear weapons. “In the current context”, they argued, “the capacity to build nuclear weapons is essential to create deterrence and to guarantee national security”, especially while “the enemy is trying to weaken” Iran’s deterrent capabilities and “resistance forces”.¹⁵ Western press coverage amplified these internal demands,¹⁶ shaping the diplomatic environment and deploying proliferation threats as a substitute for the strategic signaling available to nuclear-armed states. However, no comparable surge in such declarations was observed after the Israeli and U.S. strikes, only reiterations that Iran would “continue” its nuclear program. This more muted posture might be part of a broader effort to diminish the risk of further military action, by reducing threat perceptions in Israel and the U.S.

Thus, Khamenei warning against a potential U.S. strike – issued before resuming negotiations in March 2025 – appears rather hollow at this stage: “We are not pursuing nuclear weapons; if we were, we would have produced them by now. However, we will respond decisively to any potential strike”, said the Supreme Leader.¹⁷ Together, these developments expose a widening gap between Iran’s formal nuclear doctrine, still grounded in strategic ambiguity and religious prohibition, and an increasingly vocal domestic chorus calling for a shift toward overt deterrence.

Finally, it is worth noting that these discourses are unfolding within a broader geopolitical climate in which nuclear weapons appear ever more desirable, accompanied by a growing disinhibition around nuclear threats, rhetoric, and proliferation. Since the onset of Russia’s full-scale war of aggression against Ukraine, several Ukrainian officials and Western commentators have argued that Ukraine should have retained the Soviet nuclear weapons once stationed on its territory, rather than relinquishing them in exchange for security guarantees under the Budapest Memorandum – guarantees that were ultimately violated by Russia. Although Ukrainian experts themselves have long debunked this claim, the narrative that only nuclear weapons can effectively deter invasion or large-scale attacks by a nuclear-armed state is nonetheless gaining traction.¹⁸

The crisis of confidence in U.S. extended deterrence in both Europe and Asia has also led some states such as South Korea to make explicit references to the possibility of developing their own nuclear weapons – without eliciting strong criticism from their Western allies. This situation risks creating a double standard: as signatories of the Non-Proliferation Treaty (NPT), neither Iran nor South Korea is permitted to pursue nuclear weapons. Such developments appear to confirm the use of proliferation threats, doctrinal change, or withdrawal from the NPT¹⁹ as bargaining chips – whether to obtain greater commitments from a security guarantor (in the case of Seoul) or greater negotiating space (as with Tehran).

These examples also underscore a growing asymmetry in global nuclear governance: some states can allude to or even pursue nuclear options with limited consequences, while others – particularly in the Global South – are swiftly sanctioned for similar signals. This double standard deepens frustration and further erodes trust in the non-proliferation regime, making rhetorical escalation an increasingly attractive instrument for those who feel structurally disadvantaged. For example, in the aftermath of the U.S. and Israeli strikes, some Iranian academics described their country as facing “nuclear apartheid”, where two nuclear powers could attack their nuclear facilities without drawing any criticism from the Western world. This reflects the sense of “selective non-proliferation” analyzed by Hassan Elbahtimy in his contribution to this SALAM series.²⁰

In this light, Tehran’s recent statements are not mere domestic signaling. They are designed to resonate externally, and particularly with Western audiences, as a form of strategic messaging. In doing so, Iran is engaging in what might be called performative deterrence: a rhetorical escalation aimed at compensating for its eroding conventional strength, but one that also heightens the risk of dangerous misperceptions.

The European response: an alignment with the U.S.?

Iran’s increasingly assertive nuclear rhetoric may be proving counterproductive by provoking a more confrontational response from European parties to the JCPOA – especially France, which appears to have taken a leading role on this issue, echoing its more assertive pre-JCPOA policy. Between 2018 and 2024, French statements on Iran’s nuclear program were largely coordinated with its E3 partners and focused primarily on concerns over uranium enrichment, typically timed to coincide with the release of IAEA quarterly reports.

Since June 2024, however, France’s position has significantly hardened. That month, Paris sponsored and secured approval for a resolution at the IAEA Board of Governors²¹ pressing Iran to further fulfill its transparency obligations. This move was widely interpreted as an effort to put the nuclear file back on the international agenda, well ahead of the JCPOA’s expiration and to expert pressure on the newly elected Iranian government under President Massoud Pezeshkian.

Although some warned that the resolution might be unnecessarily escalatory and unlikely to influence Iranian behavior, it did not appear to trigger an immediate acceleration of nuclear activity. Most of the technical changes came months later, in autumn 2024, as tensions with Israel escalated. France’s posture evolved in parallel. In January 2025, President Macron declared at the annual ambassadors’ conference that Iran now represented the “greatest threat to French military forces” in the Middle East – a notable departure from the longstanding view that ISIS was the main concern, particularly given that French troops had not recently come under threat from Iranian-aligned actors in Iraq or Syria. In early April, the French Foreign Ministry also issued a pointed warning about the risk of military intervention if diplomatic negotiations between the U.S. and Iran were to fail. These dark predictions materialized in June 2025, when France gave firm support to Israeli strikes in the early days, invoking Israel’s right to self-defense and reaffirming that Iran should never get a nuclear weapon. However, unlike the UK and Germany – which also acknowledged the U.S. strikes – France described them as “concerning” for regional stability and called for de-escalation and a return to the negotiating table.²² In parallel, the E3 still retains the option to activate the JCPOA’s snapback mechanism – the reimposition of UN economic sanctions on Iran –should negotiations break down before October 2025.

Conclusion

Iran’s rhetorical shift regarding its nuclear program reflects more than symbolic defiance. It signals a deeper strategic recalibration, rooted in the erosion of its conventional deterrent triad – proxies, missiles, and strategic ambiguity – and shaped by an increasingly volatile regional and global security environment. While Iran’s formal doctrine remains unchanged, the growing visibility of hardline voices suggests that rhetorical escalation now serves as a compensatory form of deterrence, heightening the risk of misperception and unintended escalation. The limits of this strategy became evident in June 2025, when it failed to prevent direct military intervention by Israel and the U.S. on several nuclear and military sites in Iran. As a result, the Supreme Leader is now faced with a tough choice about the future of Iranian deterrence.

The recent framing of Iran as a threat to the European continent, despite the limited number of conventional missiles capable of reaching Europe and the absence of Iranian threats toward European countries, appears to reflect a partial alignment of European policy with that of the United States. It allows European countries, especially the E3, to maintain closer proximity with the U.S. at a time when discussions may be more difficult on other topics, such as the war in Ukraine. The tacit support for Israel’s actions on Iran could also serve as leverage in negotiations over a ceasefire in Gaza, where the EU’s position is finally shifting toward stronger criticism of Tel Aviv. It may also signal a desire by European actors to secure a role in U.S.-Iran negotiations, should they resume after the strikes – talks in which rhetoric, media positioning, and diplomatic signaling play a more significant role than ever. However, by showing further leniency toward Israel, the “West” faces greater accusations of double standards from countries in the Global South, ultimately undermining its long-term credibility on the international stage.

Finally, this shift carries normative implications. If European leaders frame Iran as a military threat while downplaying or ignoring nuclear signaling from their own allies, they risk undermining the very norms they claim to defend. In doing so, they may contribute to the erosion of the global non-proliferation regime.²³