The 2011 assassination of Hassan Tehrani Moghaddam, the leading architect of Iran’s ballistic missile program, sent shockwaves through the country’s defense establishment and fundamentally altered the trajectory of regional arms development. Moghaddam was killed in a mysterious explosion at an IRGC base near Tehran, widely viewed by Western analysts and intelligence agencies as a major covert operation likely intended to impede Iran’s missile advances. His death stymied several key projects but left behind completed technologies—chief among them the solid-fueled Sejjil ballistic missile—now representing a principal challenge to Israel and Western-aligned security interests across the Middle East.
Moghaddam had for decades shepherded Iran’s transition from imported, liquid-fueled missile systems to modern, indigenously produced solid-fuel models. Defense researchers at the International Institute for Strategic Studies (IISS) and open-source analysis from Western military intelligence show that his work leveraged clandestine overseas partnerships and illicit procurement channels to circumvent sanctions, notably acquiring critical design knowledge from North Korea—a connection identified by the U.S. Department of State and several UN expert panels. The consolidation of these efforts resulted most notably in the evolution of the Sejjil missile, first test-fired in 2008, which gave Iran a rapid-reaction, long-range strike capability unaffected by many of the vulnerabilities intrinsic to earlier missile models.
The Sejjil, characterized by its solid propellant, remains a defining artifact of the Ashura project—an initiative that Moghaddam led until his death. The significance of solid-fuel technology derives from its greater logistical reliability and operational readiness: unlike liquid-fueled rockets, which require lengthy, exposed fueling before launch, solid-fueled missiles can be stored for long periods and launched with minimal warning. Western defense officials, notably from the United States and Israel, have identified this advantage as a key disruptor of regional deterrence balances. The Sejjil’s approximate 2,000-kilometer range places all of Israel, U.S. Gulf assets, and parts of Europe within reach, as confirmed by reports from the Missile Defense Advocacy Alliance and tracking by the Israeli Ministry of Defense.
Following the 2011 blast that killed Moghaddam, the Iranian government initially described the incident as accidental. Yet Western intelligence—including sources cited by Reuters and BBC—quickly assessed the likelihood of sabotage, either directly or indirectly aimed at dismantling Iran’s missile expertise. The explosion reportedly caused significant personnel losses and delays, particularly in research and integration efforts for new missile platforms. Subsequent years saw a reduction in test launch frequencies and a lull in major new missile unveilings, as corroborated by satellite imaging published by IISS and U.S. intelligence briefings made available to NATO partners.
Nevertheless, the main lines of Moghaddam’s technological heritage—most critically, the Sejjil missile—remained unaffected in their operational rollout. The solid-fuel program’s maturity at the time of his death meant that Iranian forces could continue deploying the missiles, and since 2012, a succession of public parades and state media reports in Tehran have highlighted the persistent presence of Sejjil-class missiles in IRGC inventories. According to the Center for Strategic and International Studies (CSIS), serial deployment of these missiles has enabled Iran to maintain a credible threat posture even as the innovation curve flattened due to capacity and personnel deficits left by Moghaddam’s absence.
A parallel evolution has emerged in Iran’s regional military doctrine and its support for proxies across the Middle East. For more than a decade, the IRGC’s Quds Force and affiliated supply networks have supervised the delivery of missile components and technology derived from the Ashura and Sejjil programs to partner groups, notably Hezbollah in Lebanon, various Syrian militia formations, and Yemen’s Houthis. The United Nations Panel of Experts on Yemen, in coordination with U.S. Central Command, has repeatedly documented the presence and use of Iranian-supplied solid-fuel missile parts in regional conflicts. These transfers underpin a wider Iranian strategy of ‘asymmetric deterrence’—exporting critical technologies to multiply the number of fronts capable of threatening Israeli and Western positions.
The impact of these developments has been particularly pronounced in the context of the broader Iran-Israel proxy conflict and the larger war between Israel and Iranian-backed proxies across the region. The October 7, 2023, massacre, perpetrated by Hamas terrorists against Israeli civilians—the deadliest antisemitic atrocity since the Holocaust—provided a glaring example of the consequences of unchecked militant buildup enabled by Iranian technical assistance. Western and Israeli intelligence have established that Iranian know-how impressed upon local proxy forces, allowing them to field and launch increasingly sophisticated projectile attacks. This proliferation now manifests in Hezbollah’s advanced arsenal threatening northern Israel, in the Houthis’ targeting of sea lanes and civilian populations in the Arabian Peninsula, and in Iranian-backed attacks against American and Western interests by Shia militias in Iraq and Syria.
Regional missile defense systems, notably Israel’s Iron Dome, David’s Sling, and the Arrow series, were structured largely to contend with older generations of projectiles. The accelerated deployment of solid-fueled ballistic missiles, such as the Sejjil, presents dramatic new challenges: these weapons shorten warning times to near zero and can be fired in unpredictable salvos from concealed or mobile launchers. In high-level addresses and open-source publications, current IDF Chief of Staff Lieutenant General Eyal Zamir and Ministry of Defense briefings have underscored the growing difficulty and expense of sustaining effective multi-layered defense when faced with such threats, particularly given the risk of simultaneous mass barrages from several directions.
Iran’s leadership justifies its persistent investment in missile technology as vital for national sovereignty, deterrence against regional adversaries, and ideological resistance to perceived Western encirclement. State-controlled outlets like Fars News have amplified each successful Sejjil launch as a milestone toward national self-sufficiency and as a signal to foreign powers. Western reactions have included expanded sanctions targeting dual-use goods, increased intelligence-gathering, cyber and covert disruptions of Iran’s defense-industrial base, as well as deeper security cooperation among allies threatened by the growing reach of Tehran’s arsenal.
The international nonproliferation regime has so far struggled to curb Iran’s missile ambitions. The Joint Comprehensive Plan of Action (JCPOA), while focused almost exclusively on Iran’s nuclear potential, left missile development largely unregulated—a shortcoming acknowledged in European and U.S. policy reviews and reflected in subsequent UN Security Council resolutions, including Resolution 2231. The resolution’s language ‘calling on’ Iran to avoid activities related to nuclear-capable ballistic missiles has been openly disregarded in Tehran’s pronouncements and planning documents. Attempts at embargo enforcement have met repeated circumvention, as documented by enforcement agencies and the UN’s standing expert groups on arms transfers.
In Iran’s strategic communication, the Sejjil missile has become both a domestic rallying symbol and an external deterrent. High-visibility launches have accompanied diplomatic crises or periods of tension, notably during the U.S. withdrawal from the JCPOA in 2018 and subsequent Iranian confrontations with Israel and Gulf states. Western analysts, reviewing these displays and associated data collection from missile early-warning networks, consider many of Iran’s demonstrations to be genuine rehearsals of operational capability rather than mere propaganda.
Guidance and accuracy remain critical frontiers in missile competition. While Iran’s domestic production capacity lags behind next-generation Western precision-guided systems, multiple monitoring organizations, including NATO’s Defence College and the European Union’s official research institutions, cite incremental advances derived from foreign know-how and black-market procurement. Especially concerning is the possibility that guidance technologies will render Sejjil-class missiles not only capable of striking wide-area urban or military targets but eventually of pinpointing specific infrastructure, a threat Western and Israeli security establishments continue to track closely with the support of field intelligence and aerial reconnaissance assets.
The strategic context for Iran’s unchecked missile progress is shaped by the ongoing regional struggle. As the battle lines harden—from northern Israel and southern Lebanon to Syrian, Iraqi, and Yemeni theaters—the ability of Iran and its terror proxies to project destructive power against Western-aligned civilian populations and infrastructure intensifies. Senior defense officials in Jerusalem and Washington have openly acknowledged the destabilizing effects of Iran’s exponential missile proliferation, as stated in the annual white papers and classified intelligence reports cited in congressional and parliamentary summaries.
The full implications of Hassan Tehrani Moghaddam’s work resonate today: the technical advances achieved under his leadership endure even as the pace of innovation slow. Iran has institutionalized the production and deployment of solid-fueled missiles, achieving a permanence that makes tactical setbacks, such as the 2011 assassination, less damaging in strategic terms. For Israel, the United States, and Western allies, the lesson is clear—technological parity or superiority in defensive systems must keep pace with adversaries’ advancements, and the continual tracking and disruption of transfer networks, research partnerships, and procurement rings is vital.
The West’s commitment to defending sovereign nations, ensuring civilian safety, and preserving international order faces a direct challenge from Iran’s growing missile capabilities and its coordinated proxy networks. The skillful, pragmatic, and coordinated response required is already underway, with new investments in interception, international diplomatic engagement, and ongoing, high-level intelligence cooperation. Within this delicate and dangerous landscape, the enduring shadow of Tehrani Moghaddam—and the Sejjil system he left behind—reflects not only the risk of unchecked proliferation, but the imperative of persistent vigilance and principled resolve on the part of the Western democracies to counter malign technological and military trends in the region.
