Executive Summary

For Iran, protecting its maritime borders and the safeguarding of its industrial, military, and oil infrastructure along the coastline constitute a geostrategic imperative. While the Zagros Mountains have historically served as a natural barrier against land-based invasions, contemporary military technologies necessitate additional layers of defence.

In light of increasing Israeli hostility and the push for direct confrontation between the Tel Aviv–Washington axis and the Islamic Republic of Iran, assessing Tehran’s deterrence strategy in the region has become critical.

Although a direct US military strike on Iran does not currently appear to be a strategic priority for Washington, mounting pressure from Tel Aviv could prompt a more assertive American posture—evidenced, for instance, by the redeployment of military assets to Diego Garcia.

Information Background

Iran’s deterrence strategy in the Persian Gulf is a sophisticated blend of military tactics, ideological rhetoric, the deployment of regional proxies, and naval/missile posturing. The primary aim is to prevent aggression by the United States and Israel through the following elements:

• Deployment of advanced missile capabilities and anti-access/area denial (A2/AD) systems in the Strait of Hormuz.
• Redundancy and Self-Reliance: Iran has built its defence systems with redundancy in mind, meaning that multiple systems can perform the same function (this plan includes decentralisation of Command).
• Utilisation of non-state actors such as Hezbollah, Shia militias in Iraq, and the Houthis in Yemen to exert asymmetric pressure.
• Emphasis on a doctrine of “defence in depth” and “assured retaliation,” aiming to deter attacks by threatening regional escalation; Tehran’s military strategies are designed to slow down or deny an adversary’s advance through a combination of preemptive and retaliatory measures.
• Leveraging geography.
• Conduct of naval exercises and simulated closures of the Strait to signal coercive capabilities.
• Integration of religious and revolutionary discourse with strategic messaging, adding a layer of unpredictability to Iran’s red lines.
• Integration of artificial intelligence (AI) into its weapons systems.
• Cyber warfare.
• Creation of economic and infrastructural dependencies with neighbouring and regional countries.
• Implementation of a “mosaic defence” system.
• Indirect negotiations.

Geopolitical Analysis

The Persian Gulf holds critical strategic and economic significance on a global scale. Iran’s geographic position along this vital corridor grants it a strategic advantage over one of the world’s most crucial chokepoints for energy transit and maritime trade.

Iran possesses anti-access/area denial (A2/AD) systems, meaning it has developed and deployed a range of military capabilities designed to prevent or deter hostile forces from entering a specific area (anti-access)—such as US naval or air assets approaching the Iranian coastline or transiting through the Strait of Hormuz—and to restrict the operational freedom of those forces within that area (area denial), thereby making effective operations within the contested zone difficult or prohibitively costly.

In practical terms, Iran’s A2/AD posture includes medium- and long-range ballistic and cruise missiles capable of striking enemy bases, vessels, or infrastructure across the region; air defence systems intended to deter or neutralise aerial incursions; naval mines, submarines, and fast attack craft aimed at threatening maritime traffic in the Strait of Hormuz; and an array of radars, drones, and electronic warfare tools used to monitor and disrupt adversary activities.

To enhance its ability to use the Strait of Hormuz as a geopolitical and negotiating lever, Iran, under the Rouhani administration, inaugurated the Goreh-Jask pipeline. This strategic infrastructure transports crude oil from inland production sites directly to the Gulf of Oman, effectively bypassing the Strait. By enabling exports through waters beyond the chokepoint, the pipeline allows Iran to mitigate the impact of potential blockades on its own oil flows while preserving the option to disrupt rival shipments transiting the Strait.

Tehran effectively used the war with Saddam Hussein as a unique opportunity for live combat training and closely observed US military interventions in Iraq, Afghanistan, and the Balkans to adapt its own defence infrastructure in response to Washington’s operational patterns. The initial structural adaptations were based on the experience gained from US air operations in Iraq, where strategic infrastructure, such as telecommunications networks, was systematically attacked and rendered inoperable.

Iran’s naval forces consequently developed passive defence strategies, designed to leverage the country’s favourable geography to ensure continuity of operations even after a potential large-scale initial strike. Passive defence refers to non-weaponized protection measures, such as concealed platforms along Iran’s rugged coastline—marked by numerous islands and inlets—and a network of underground tunnels and bunkers built within these features.

Anticipating the likelihood of an aerial campaign from external actors, Iran’s military leadership also undertook a decentralisation of its command structure. This led to the development of the so-called “mosaic defence” plan, intended to enhance the resilience of Iran’s command-and-control (C2) system under hostile attack. The Islamic Revolutionary Guard Corps (IRGC) restructured its control architecture into 31 separate commands—one for Tehran and one for each of Iran’s 30 provinces.

At the naval level, the strategy includes concealing fast attack craft within coastal bunkers and inlets, allowing for their relocation in the event of an attack. These vessels are pre-assigned to operate in designated zones, ensuring mission continuity even if central command structures are compromised.

Retaliation policies also comprise the practice of targeting vessels in the Persian Gulf, which originated in response to Iraqi attacks during the Tanker War (1984–1988). At the time, Iran’s lack of effective anti-ship missiles and compelled it to develop innovative and unconventional tactics, many of which continue to define the operational methods of the Islamic Revolutionary Guard Corps Navy (IRGCN) today. These included the use of small submarines, extensive naval mine deployment, and large-scale swarming tactics involving fast attack craft. Recently, the IRGC unveiled new naval capabilities, such as a warship armed with 600-kilometre-range missiles.

Such asymmetric maritime strategies—initially conceived to compensate for conventional military inferiority and limited resources—laid the groundwork for what has become Tehran’s modern doctrine of asymmetric warfare, which incorporates elements of guerrilla-style operations.

Iran also operates an integrated surveillance network composed of electro-optical sensors, radar systems, and acoustic arrays, along with an expanding fleet of drones with an allegedly 2,000-kilometre range, now increasingly enhanced with AI capabilities. These assets serve multiple purposes: they enable real-time targeting for retaliatory strikes in the event of Iranian vessels being seized by hostile powers abroad, and they can also facilitate short-term interdictions aimed at technological reconnaissance of Western military and commercial equipment.

While it is uncertain whether Russia or China would intervene directly to defend Iran in the event of an attack, the recent joint maritime exercise “Maritime Security Belt 2025” has strengthened Iran’s defence posture, reinforcing its strategic partnerships and demonstrating both strength and operational capability. Indirect support, such as the provision of arms or intelligence, should not be ruled out as a potential form of assistance from these powers.

Over the past year, Tehran has conducted several military exercises to assess its operational capacity and speed (like swift transfer of troops and equipment). In addition to the naval exercise with Russia and China, there have been various drills aimed at testing Iran’s defensive capabilities against aerial attacks. These exercises have highlighted certain vulnerabilities within Iran’s defence system. The most intense military exercises in decades, “Eqtedar 1403” (Power) drills, began on the 28 December 2024. The first phase, “Great Prophet 19”, involved IRGC ground forces, while the second phase tested the air defence forces. Particularly, they concentrated their effort in the defence capacity of the country’s nuclear facilities, such as the Arak reactor in Khondab, Natanz, and Fordow, which are the most likely target of a US/Israeli attack.

Finally, ideology remains a central tool in the indoctrination of both the IRGC and Iran’s regional proxy forces. Concepts such as martyrdom and pre-emptive jihad have served to expand Iran’s influence across the broader Middle East. The IRGC is fundamentally a religious-military institution: after God, allegiance is pledged to the Velayat-e Faqih (Guardianship of the Islamic Jurist), embodied by Supreme Leader Ali Khamenei. Strategic decisions—such as a potential closure of the Strait of Hormuz—are made directly by Khamenei himself.

Conclusion

Throughout the year, Iran has conducted numerous military exercises aimed at mitigating the potential threat of a US/Israeli attack. With the US military build-up in Diego Garcia and their expanding presence in neighbouring countries such as Armenia, Tehran has grown increasingly concerned about its security. Iran’s defence doctrine is specifically crafted to address the technological disparity with Western powers like Washington and Tel Aviv, ensuring resilience in the face of a large-scale initial assault while maintaining the capacity for rapid retaliation.

However, both Iranian and US military manoeuvres may merely serve as displays of strength, as ongoing negotiations could be taking place behind the scenes. That said, the influence of Israel over President Trump should not be underestimated, especially given the complex dynamics of their strategic relationship.

Moreover, Tehran has worked to strengthen ties with neighbouring countries to discourage them from offering their airspace or bases for attacks against Iran. Tehran has also threatened to target critical assets in those countries in retaliation for any strikes against its territory—specifically, by striking the Gulf’s oil fields, which could trigger a shockwave in global oil and gas markets, impacting both the West and the Gulf monarchies.

Author: Silvia Boltuc

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