'Unconditional Escalation' Marks Iran's Shifting Deterrence Strategy

The U.S.–Israeli February 28 joint military action against Iran quickly expanded across the region. Iran’s response to the attacks—both in regionalizing the war (horizontal escalation) and in diversifying targets and shifting red lines (vertical escalation)—can be evaluated from a deterrence perspective. Prior to Hamas’s October 7, 2023, attacks on Israel, Iran’s deterrence was based on a set of strategic principles and operational tools shaped within the framework of the Islamic Republic’s security doctrine and the experience of the Iran–Iraq War. This deterrence was largely asymmetric, consisting of three layers: the proxy layer, the missile-and-drone layer, and the threshold or potential nuclear capability layer.

Instead of attempting to directly defeat Israel—whose geography and air defense layers limited such an objective—Iran sought to weaken the supporting infrastructure that underpinned Israel’s operational freedom (Iran Analytica, March 25). Iran’s regionalization of the war is also framed within Tehran’s “Samson Doctrine,” a strategy aimed at creating maximum chaos across the Persian Gulf region and the global economy (Arab Gulf States Institute, March 13).

Iran has notably adopted an “eye for an eye” approach (Asr Iran, March 10). This approach is based on proportionality, thereby discouraging the United States and Israel from targeting Iran’s critical interests, particularly energy infrastructure. According to Thomas Schelling’s theory, deterrence is not only dependent on the ability to attack but also on the risk of uncontrolled escalation. In this regard, Iran aims to create a situation in which events could spiral out of control if the opposing side does not retreat from its threats (Schelling, 1960). [2] After three weeks of war, Iran’s strategy shifted from purely retaliatory responses to an offensive phase. For example, Tehran quickly warned that its response would include attacks on regional energy and technology infrastructure and targeting U.S. financial institutions if the United States carried out attacks against Iran’s electrical infrastructure (Asr Iran, March 22).

This new pattern showed that Iran is attempting to turn military asymmetry into a strategic lever through expanding the battlefield and linking escalation across multiple domains. By expanding its targets to energy infrastructure and economic assets in the Persian Gulf, Iran increases pressure on its enemies while simultaneously raising tensions with neighboring countries (Iran Analytica, March 25). Although Tehran hopes these countries will seek de-escalation rather than intervention, the immediate consequence is regional instability and an increased risk of miscalculation and rapid escalation (Al Monitor, March 24).

After the second round of Iranian–U.S. negotiations in Geneva on February 17, the IRGC Navy temporarily closed the Strait of Hormuz during a large-scale exercise called “Smart Control of the Strait of Hormuz” (Fars News Agency, February 18). Iran then officially closed the waterway following the start of the conflict. This action was based on Tehran’s belief that symbolic responses to the United States are ineffective and merely perpetuate cycles of pressure and subsequent strikes. Accordingly, Iran not only closed the Strait but moved toward “targeted disruption of the global energy market,” including attacks on production facilities, pipelines, export terminals, or oil tankers. Tehran’s logic was based on deterrence through the creation of systemic risk in the energy market (KEDM Public Radio, February 16).

From Iran’s perspective, keeping the Strait of Hormuz closed would shift the regional balance of power in its favor and force countries highly dependent on Persian Gulf energy to recalibrate their geopolitical considerations toward Iran. Thus, the continuation of war and rising uncertainty in the region could strengthen Iran’s geopolitical role. In times of crisis, control over strategic chokepoints and regional deterrence becomes more significant. Consequently, Iran aims to leverage its geographic position and strategic capabilities to increase its bargaining power, influencing the behavior of both regional and extra-regional actors toward more cautious engagement with Tehran (Mehr News Agency, March 14).

According to Iranian officials, after the war, a “new protocol” is to be developed to ensure the safe passage of ships and define specific conditions (Ministry of Foreign Affairs of the Islamic Republic of Iran, March 17). The plan, titled the “Strategic Action Law for Peace and Endogenous and Sustainable Development of the Persian Gulf Region,” includes four sections: Maritime security, environmental pollution charges, navigation service fees, and the establishment of a regional development fund (Fararu, March 30). The outlook for this new protocol faces challenges, however, including conflict with the United Nations 1982 Convention on the Law of the Sea. Furthermore, unlike the Bosporus and Dardanelles—controlled by a single country (Türkiye)—the Strait of Hormuz is shared between Iran and Oman, which may not accept Iran’s unilateral actions. 

Iran’s security strategy has been based on regional strategic depth, seeking to transfer conflicts beyond its borders. This strategy made use of proxy forces known as the “Axis of Resistance,” including Hezbollah, Hamas, Islamic Jihad, Iraq’s Popular Mobilization Forces, and Yemeni Houthis. Despite the weakening of this network—especially its ability to generate simultaneous firepower after Hamas’s October 7 attack—the remnants of these forces have been activated as tools to expand the battlefield. The goal is to maximize the costs of conflict, with proxies contributing to regional destabilization. Their political-strategic function has remained an important tool for Iran, despite a decline in their operational capabilities (Atlantic Council, April 9, 2024; Tabnak, March 15).

Hezbollah, Iraqi PMF, and Yemeni Houthis have all entered the conflict. Hezbollah and the Houthis focused on targeting Israel, while Iraqi forces targeted U.S. and Israeli positions not only in Iraq but also in Kuwait, Jordan, and Bahrain. Offensively, the Houthis—beyond their ability to close the Bab al-Mandab chokepoint—possess the capacity to target U.S. military assets within the range of their strategic arsenal, which includes long-range drones and missiles (New Arab, March 30).

After the war, Iran is expected to focus on preserving and rebuilding proxy groups through tactical flexibility, resistance to disarmament, and shifts in support priorities. In Iraq, Iran’s approach is heavily influenced by U.S. pressure and the central government’s will to disarm militias. Unlike in the past, Tehran has signaled to these groups that they should cooperate with disarmament plans to avoid a destructive confrontation with the United States (Deutsche Welle, April 7, 2025). Iran’s goal is to ensure these groups’ survival by gradually integrating them into Iraq’s official state structure rather than maintaining them as independent militias (Deutsche Welle, August 10, 2025).

Lebanon remains the most sensitive point for Iran. A different approach has been adopted due to the Lebanese government’s alignment with U.S. disarmament plans for Hezbollah. Tehran openly opposes any disarmament of Hezbollah and considers it a red line (Khabar Online, August 7, 2025). Therefore, despite some rhetorical moderation under diplomatic pressure, Iran coordinates with Hezbollah to resist disarmament through political means (Al Alam, April 24, 2025). Tehran’s immediate goal is to prevent the loss of Hezbollah’s existing capabilities—especially its large missile arsenal—as a key deterrent against Israel (European Council on Foreign, June 5, 2024).

With Hamas and Hezbollah significantly weakened, the Yemeni Houthis have become Iran’s most powerful regional ally (Euro News, December 8, 2025; New Arab, March 30). The Houthis view themselves as partners, however, rather than as fully controlled proxies. Despite this, their ability to destabilize the Red Sea, Arabian Sea, and Gulf of Aden increases their importance for Iran. If Tehran survives the current conflict, it will retain the ability to support its allies, even if some, such as Hezbollah, are weaker than before (New Arab, March 3).

Iran has moved away from its traditional deterrence doctrine and adopted a strategy of “unconditional escalation.” This strategy involves regionalizing conflicts, targeting energy and financial infrastructure, closing the Strait of Hormuz, and activating proxy forces. This strategic shift—designed to turn military asymmetry into an economic-geoeconomic lever—increases the risk of regional instability and unpredictable escalation. Consequently, it could redefine Iran’s role as a chokepoint power and lead to a new balance in the Middle East. In the future, therefore, maintaining control over the Strait of Hormuz, the Houthis’ capacity to control the Bab al-Mandab Strait, and missile and drone stockpiles will likely be of greater importance for Iran’s deterrence capabilities than its latent nuclear program.

Javad Heiran-Nia, Ph.D., International Relations, Director of the Persian Gulf Studies Group at the Center for Scientific Research and Middle East Strategic Studies, Tehran, Iran.

[1] http://www.jstor.org/stable/resrep28480.5.">Vatanka, Alex. “Soleimani Ascendant: The Origins of Iran’s ‘Forward Defense’ Strategy.” In Whither the IRGC of the 2020s?: Is Iran’s Proxy Warfare Strategy of Forward Defense Sustainable? New America, 2021. http://www.jstor.org/stable/resrep28480.5.

http://www.jstor.org/stable/resrep28480.5."> [2] Schelling, Thomas C. 1960. The Strategy of Conflict. Cambridge, MA: Harvard University Press.

This article appeared originally at The Jamestown Foundation's Terrorism Monitor.