Iran’s Approach to Deterrence

Iranian skyline with mountains in the background. Photo Credit: Shutterstock.

Iran’s approach to deterrence and grand strategy produces threats to different US foreign policy priorities: chiefly, non-proliferation, arms control, and regional stability, making it difficult for the United States to make and build consensus for an effective countering strategy. Iran’s desire to establish a nuclear deterrent and its use of proxies to cause instability throughout the region hinders US policymakers’ ability to craft an effective and enduring strategy that can span administrations. As a result, managing the threats posed by Iran has proven extremely challenging for US foreign policy.

Iran seeks to create a deterrent threat in two primary ways – by pursuing a nuclear arsenal and using proxies and clients to advance its strategic interests across the region. Obtaining a nuclear weapon is an attractive option for deterrence because establishing a nuclear arsenal costs less than maintaining a conventional army. A nuclear weapon is also a more certain deterrent as a conventional army could, in the event of war, be overcome. Additionally, maintaining a nuclear arsenal would create great uncertainty as to whether Iran desires a minimum, defensive, or offensive nuclear deterrent.[i]

Iran’s use of proxies and clients across the region fuels instability and grants Iran influence in the domestic affairs of its neighbors. Driven by its isolation and perception that it is surrounded by threats, Iran’s use of proxies serves multiple purposes. Short of gaining significant influence, proxies can distract regional states, forcing allocation of resources to conflicts and the resulting instability and refugee flows. Importantly, this grants Iran allies throughout the region, many of whom possess significant political or military clout.[ii] Iran’s ideal situation is that a proxy force becomes influential in the politics or military of the state in which it is operating.

Hezbollah represents the most successful version of this effort.[iii] In Iraq, Iranian militias have secured a place in the Popular Mobilization Forces, an official part of Iraqi security structure,[iv] and Iran has curried favor with many Iraqi politicians.[v] In Yemen, Iranian support for the Houthis grants Iran a front to challenge Saudi Arabia while maintaining plausible deniability. In Syria, Iranian proxies helped prevent the overthrow of Iran’s sole state ally, Bashar al-Assad. The expansion of Iranian interests into the domestic politics of its neighbors ensures Iran will be a player in not just a military sense, but in impacting policy and strategy for years to come.

These two lines of effort combine to create added pressures to US non-proliferation priorities. If Iran were to acquire a nuclear weapon, concerns over whether it would provide one of its clients or a terrorist organization with a weapon would dominate American threat management efforts.

Iran’s strategy has serious flaws and challenges. Although the Islamic Republic enjoys a level of plausible deniability through these relationships, it is unclear how sustainable this policy is. First, Iran must strike a delicate balance in its use of clients, such that client actions do not provoke an aggressive response against Iran. Constant low-level provocations may, over time, create sufficient incentives for an escalation. Thus, risk management calculations at the operational level are critical to achieve its strategic goals.

Second, the efficacy of Iran’s client and proxy strategy is currently under question. Ongoing protests in Iraq[vi] and Lebanon[vii] could signal the infeasibility of establishing long-term clients throughout the region. Persistent local backlash will diminish Iran’s leverage over time, complicating Tehran’s strategy. At the same time, although it is unclear what degree of leverage Iran will maintain in post-conflict Syria, it preserved an important ally in the Assad regime.

These behaviors create tension and conflict among US foreign policy priorities, limiting the formulation of a consistent strategy for managing Iranian threats. Iran’s nuclear ambitions put pressure on nonproliferation efforts. Its missile capabilities trouble arms controllers and disarmament initiatives. Proxies and clients challenge regional stability and complicate allied relationships. For example, due to civilian deaths resulting in the Saudi-led intervention in Yemen in July 2019, Congress voted to block an $8 billion arms deal to the kingdom, which President Trump vetoed.[viii] Given this wide range of pressures, US policymakers must constantly recalculate which priorities to demand attention. Conflicting priorities and the geopolitics of the day can produce significantly different approaches to the problem-set.

Differing approaches towards Iran are most clearly visible in US domestic politics. In 2015, President Barack Obama prioritized nonproliferation and leveraged economic sanctions to pressure Iran into signing the Joint Comprehensive Plan of Action (JCPOA) to prevent Iran from developing a nuclear weapon. Republicans and even a few Democrats in Congress, prioritizing Iran’s regional behavior and ballistic missile acquisition, criticized the JCPOA for granting the regime too many economic incentives while doing nothing to curb its use of proxies and other illicit activities. The lack of Congressional support and consensus for the JCPOA ensured it did not become a treaty, granting President Trump the flexibility to either stay in the agreement or break it. Choosing the latter approach and coupling it with punitive economic sanctions, the administration believes it can curb Iran’s behavior in the region and prevent it from obtaining a nuclear weapon. But building a consensus on particular threats will remain difficult because of these different perspectives and approaches. A sustainable strategy for countering Iran needs to encompass the various Iranian threats as well as receive national buy-in.


[i] Paul Bracken, The Second Nuclear Age: Strategy, Danger, and the New Power Politics (New York: St. Martin’s Press, 2013), 142-148.

[ii] Afshon Ostovar, “The Grand Strategy of Militant Clients: Iran’s Way of War,” Security Studies 28:1: 183.

[iii] Tony Badran and Jonathan Schanzer, “Lebanon, Hezbollah and Iran’s Emerging Client State,” The Wall Street Journal, September 18, 2019,

[iv] John Hannah, “Iran-Backed Militias Are In Iraq to Stay,” Foreign Policy, July 31, 2019,

[v] Tim Arango, James Risen, Farnaz Fassihi, Ronen Bergman and Murtaza Hussain, “The Iran Cables: Secret Documents Show How Tehran Wields Power in Iraq,” The New York Times, November 18, 2019,

[vi] Jane Arraf, “’They Have Stolen Everything From Us’: Iraq’s Anti-Government Protests Continue,” NPR, November 5, 2019,

[vii] Timour Azhari, “One month on: Hope, defiance as Lebanon protests persist,” Al-Jazeera, November 17, 2019,

[viii] Karoun Demirjian and Colby Itkowitz, “Trump vetoes Congress’s attempt to block arms sales to Saudi Arabia,” The Washington Post, July 24, 2019,

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