Coercive Diplomacy and the Limits of Credible Bargaining in the U.S.–Iran Standoff

Disclaimer: This article was written before 28 February, 2026

Lou Cardot is a third-year student at the University of Toronto, pursuing a double major in Law and Political Science, with a minor in European Affairs. She came to UCL on exchange this year. Raised in Paris and Washington, D.C., Lou’s interests include human rights, gender equality, and immigration policy. This summer, she interned for Deloitte in Compliance. She also writes as a freelancer for the French Ministry of Defense and various law reviews across Europe and North America. (lou@cardot.me | LinkedIn)

Introduction: Conceptualizing Negotiation Under Coercion

Diplomacy presupposes a bargaining space in which adversaries, despite profound disagreement, recognize negotiation as a mutually intelligible and potentially stabilizing process. That premise erodes when talks are explicitly conditioned on coercion.

In July 2015, Iran and the P5+1 powers (United States, United Kingdom, France, Germany, Russia, and China) concluded the Joint Comprehensive Plan of Action (JCPOA), an agreement designed to constrain Iran's nuclear program in exchange for sanctions relief.[1] Under the deal, Iran accepted strict limits on uranium enrichment levels (capped at 3.67%), reduced its stockpile to 300 kilograms, dismantled advanced centrifuges, and subjected its facilities to intrusive inspections by the International Atomic Energy Agency (IAEA).[2] In return, the United States and its partners agreed to lift nuclear-related economic sanctions.[3]

In May 2018, the United States unilaterally withdrew from the agreement and reimposed sweeping sanctions as part of what became known as the “maximum pressure” campaign.[4][5] Since then, diplomatic engagement between Washington and Tehran has oscillated between indirect negotiations and escalatory confrontation, including regional proxy conflicts and the January 2020 U.S. drone strike that killed Iranian General Qassem Soleimani.[6]

This article examines the viability of diplomacy under conditions of explicit coercion through the lens of U.S.–Iran relations since the withdrawal from the Joint Comprehensive Plan of Action (JCPOA). Situating the present impasse within the broader framework of coercive diplomacy, it argues that threat-based bargaining systematically undermines diplomatic credibility, hardens domestic political constraints, and incentivizes strategic defiance rather than compromise. Far from constituting an aberration, the U.S.–Iran case shows a pattern in which great-power reliance on sanctions and deterrence narrows the space for durable negotiation, privileging short-term leverage over long-term conflict management.

Coercive Diplomacy and Commitment Credibility

Coercive diplomacy, as classically theorized, seeks to compel behavioral change through the threat or limited use of punishment, while stopping short of war. Its success depends on a narrow equilibrium: pressure must be sufficient to induce negotiation but not so overwhelming as to eliminate the adversary's incentive to bargain.

The pioneers of coercive diplomacy, Alexander George and Thomas Schelling, emphasize that coercion operates not through brute force alone but through communication and signals about future restraint, reversibility, and the possibility of accommodation.[7][8] Yet modern applications of coercive diplomacy frequently collapse this distinction. When negotiation is explicitly framed as contingent on sustained pressure, the coercing state transforms diplomacy from a forum for mutual concession into an extension of compellence. Under such conditions, talks cease to function as mechanisms for resolving disputes and instead become instruments for formalizing asymmetrical outcomes.

This directly implicates credibility: a state asked to negotiate under threat must assess whether any resulting agreement will be respected once compliance is achieved, or whether coercion will simply recalibrate to extract further concessions. Where that credibility is absent, refusal to negotiate may constitute a rational strategic response rather than simple obstinacy.

The JCPOA Case

The JCPOA represents the most significant diplomatic breakthrough in U.S.–Iran relations since the 1979 Revolution.[9] The agreement emerged after more than a decade of escalating tensions over Iran's nuclear program, particularly following the 2002 revelation of undeclared nuclear facilities at Natanz and Arak.[10] By 2010, the United Nations Security Council and the United States had imposed increasingly severe multilateral and unilateral sanctions targeting Iran's banking system, oil exports, and access to global financial networks.[11] These measures, combined with falling oil prices and domestic economic strain, materially altered Iran's cost-benefit calculus and contributed to the election of President Hassan Rouhani in 2013 on a platform of diplomatic engagement.[12]

Under the JCPOA, Iran agreed to extensive and verifiable restrictions on its nuclear program.[13] Uranium enrichment was capped at 3.67 percent, well below weapons-grade levels, and Iran's stockpile of enriched uranium was reduced to 300 kilograms for fifteen years.[14] Two-thirds of installed centrifuges were dismantled, advanced centrifuge research was constrained, and the heavy-water reactor at Arak was redesigned to prevent plutonium production.[15] Most significantly, Iran accepted intrusive inspection and verification mechanisms administered by the International Atomic Energy Agency (IAEA), including continuous monitoring of declared facilities and implementation of the Additional Protocol.[16] In exchange, the United States and its partners committed to lifting nuclear-related sanctions and reintegrating Iran into global energy and financial markets.[17]

Between Implementation Day in January 2016 and the U.S. withdrawal in May 2018, the IAEA issued multiple quarterly reports confirming that Iran remained within the agreement's enrichment limits, stockpile caps, and inspection obligations.[18] Although disputes persisted over ballistic missile development and regional proxy activity—issues deliberately excluded from the nuclear framework—the core nonproliferation bargain held.[19] The agreement thus demonstrated that sustained pressure, when paired with reciprocal and clearly sequenced concessions, could generate verifiable compromise.

However, the durability of that compromise proved contingent on domestic political continuity within the coercing state. In May 2018, the United States unilaterally withdrew from the JCPOA and reimposed comprehensive sanctions as part of the “maximum pressure” campaign.[20][21] These measures targeted Iran's central bank, energy exports, the shipping sector, and foreign firms doing business with Tehran through secondary sanctions.[22] The reversal did not follow a verified material breach but rather a change in U.S. executive policy.[23]

Commitment Breakdown After 2018

Following its withdrawal from the JCPOA in May 2018, the United States initiated what it termed a "maximum pressure" campaign designed to compel Iran to renegotiate not only its nuclear commitments but also its ballistic missile program, regional military activities, and elements of its domestic governance.[24] Sanctions were rapidly reimposed and expanded, targeting Iran's central bank, energy exports, shipping networks, metals sector, and access to the Society for Worldwide Interbank Financial Telecommunication (SWIFT).[25] Secondary sanctions penalized third-party states and corporations conducting business with Tehran, effectively weaponizing access to the U.S. financial system. Iranian oil exports, which had averaged approximately 2.5 million barrels per day in 2017, fell dramatically by 2020, severely constraining state revenue and accelerating domestic inflation.[26]

Unlike the pre-2015 sanctions regime, however, the post-withdrawal strategy lacked a clearly articulated diplomatic offramp. While U.S. officials periodically called for negotiations, the terms advanced publicly, including twelve broad demands announced by Secretary of State Mike Pompeo in 2018, extended well beyond the nuclear file and encompassed sweeping changes to Iran's regional posture and defense doctrine.[27] No credible roadmap for normalization accompanied the pressure; relief appeared open-ended and subject to recalibration even after compliance.

The problem was not coercion itself, but the absence of credible exit conditions. Sanctions generate leverage only when compliance is expected to produce durable relief. Where relief appears reversible or politically contingent, the incentive to concede diminishes. Sanctions scholarship suggests such pressure often consolidates hardline factions rather than producing moderation.[28][29]

In Iran's case, the political cost of negotiating under overt threat was especially high. The Islamic Republic's ideological foundation is partly rooted in resistance to foreign domination, particularly American intervention. Accepting expanded concessions under conditions of maximum pressure would risk domestic delegitimation and signal vulnerability. Strategic defiance, gradually exceeding JCPOA enrichment caps after 2019 while avoiding immediate weaponization, allowed Tehran to retaliate proportionally without triggering full-scale conflict. This calibrated noncompliance functioned both as leverage and as a demonstration that pressure would incur reciprocal costs.[30]

Moreover, the escalation dynamic proved self-reinforcing. In January 2020, the U.S. drone strike that killed Iranian General Qassem Soleimani further intensified hostility and narrowed diplomatic space.[31] Each side's signaling of resolve increased domestic audience costs associated with compromise. In bargaining-theoretic terms, the dispute shifted from a contest over nuclear parameters to a contest over credibility and resolve. Concession became politically riskier than endurance.

The result was leverage without exit: a sanctions regime capable of inflicting significant economic damage but structurally incapable of producing stable negotiation. Without a mutually intelligible pathway toward reciprocal de-escalation, coercion ceased to function as a bridge to diplomacy and instead became an end state in itself.

Domestic Political Constraints in Coercive Bargaining

Coercive diplomacy reshapes domestic incentives on both sides. In the coercive state, escalation signals resolve, making de-escalation politically costly.[32] In the targeted state, concession under threat generates audience costs that may outweigh material gains. Fearon's bargaining theory underscores that agreements require credible commitments; once prior commitments are reversed, future assurances lose informational value.[33] The dispute therefore shifted from bargaining over nuclear constraints to signaling reliability and resolve. Tehran's refusal to negotiate under sustained threat reflects this altered environment: without credible assurances of continuity, engagement carries a higher risk than resistance.

Works Cited

[1] European Union, Joint Comprehensive Plan of Action, July 14, 2015.

[2] International Atomic Energy Agency (IAEA), Verification and Monitoring in the Islamic Republic of Iran in Light of United Nations Security Council Resolution 2231 (2015), GOV/2016/8.

[3] European Union, Joint Comprehensive Plan of Action, July 14, 2015, Annex II.

[4] The White House, “Remarks by President Trump on the Joint Comprehensive Plan of Action,” May 8, 2018.

[5] U.S. Department of State, “After the Deal: A New Iran Strategy,” Speech by Secretary of State Michael R. Pompeo, May 21, 2018.

[6] Cooper, Helene et al., “U.S. Strike in Iraq Kills Qassim Suleimani, Commander of Iranian Forces,” New York Times, January 3, 2020.

[7] Schelling, Thomas C., Arms and Influence (New Haven: Yale University Press, 1966).

[8] George, Alexander L., Forceful Persuasion: Coercive Diplomacy as an Alternative to War (Washington, DC: United States Institute of Peace Press, 1991).

[9] European Union, Joint Comprehensive Plan of Action, July 14, 2015.

[10] International Atomic Energy Agency (IAEA), Implementation of the NPT Safeguards Agreement in the Islamic Republic of Iran, GOV/2003/40, June 6, 2003.

[11] United Nations Security Council, Resolution 1929 (2010), S/RES/1929.

[12] Ansari, Ali M., Iran: A Modern History (New York: Basic Books, 2016).

[13] European Union, Joint Comprehensive Plan of Action, July 14, 2015.

[14] Arms Control Association, “The Joint Comprehensive Plan of Action (JCPOA) at a Glance,” 2015.

[15] Arms Control Association, “The Joint Comprehensive Plan of Action (JCPOA) at a Glance,” 2015.

[16] International Atomic Energy Agency (IAEA), GOV/2016/8.

[17] European Union, Joint Comprehensive Plan of Action, Annex II, 2015.

[18] International Atomic Energy Agency (IAEA), Quarterly Reports to the Board of Governors, January 2016–May 2018.

[19] Katzman, Kenneth, Iran’s Foreign and Defense Policies, Congressional Research Service, 2017.

[20] The White House, “Remarks by President Trump,” May 8, 2018.

[21] U.S. Department of State, “After the Deal: A New Iran Strategy,” May 21, 2018.

[22] U.S. Department of the Treasury, “Iran Sanctions,” 2018–2019.

[23] The White House, “Remarks by President Trump,” May 8, 2018.

[24] U.S. Department of State, “After the Deal: A New Iran Strategy,” May 21, 2018.

[25] U.S. Department of the Treasury, “Frequently Asked Questions Regarding the Re-imposition of Sanctions,” 2018.

[26] U.S. Energy Information Administration (EIA), “Iran Crude Oil Production and Exports Data,” 2020.

[27] Pompeo, Michael R., “After the Deal: A New Iran Strategy,” The Heritage Foundation, May 21, 2018.

[28] Drezner, Daniel W., “Sanctions Sometimes Smart: Targeted Sanctions in Theory and Practice,” International Studies Review 13, no. 1 (2011): 96–108.

[29] Peksen, Dursun, “When Do Economic Sanctions Work?” Defence and Peace Economics 30, no. 6 (2019): 635–647.

[30] International Atomic Energy Agency (IAEA), Reports on Iran’s NPT Safeguards Agreement, 2019–2020.

[31] Cooper et al., “U.S. Strike in Iraq Kills Qassim Suleimani,” New York Times, January 3, 2020.

[32] Fearon, James D., “Domestic Political Audiences and the Escalation of International Disputes,” American Political Science Review 88, no. 3 (1994): 577–592.

[33] Fearon, James D., “Rationalist Explanations for War,” International Organization 49, no. 3 (1995): 379–414.