The Multilateral Signatory Coalition Outside the United States and Iran

While geopolitical analysis frequently characterizes the Joint Comprehensive Plan of Action (JCPOA) as a bilateral negotiation between Washington and Tehran, the agreement was fundamentally a highly structured multilateral treaty. Outside of the United States and the Islamic Republic of Iran, five sovereign nations were formal signatories and active participants: the United Kingdom, the French Republic, the Federal Republic of Germany, the Russian Federation, and the People’s Republic of China. In addition, the European Union (EU) participated as a distinct signatory and coordinating institution, represented by the High Representative of the Union for Foreign Affairs and Security Policy. This group of world powers was collectively designated as the P5+1 (representing the five permanent members of the United Nations Security Council plus Germany) or the E3/EU+3 (denoting the three European states, the European Union, and the three remaining global powers).

The roots of this specific multilateral configuration trace back to 2003, when the “E3” (France, Germany, and the United Kingdom) initiated direct diplomatic talks with Tehran to prevent a referral to the United Nations Security Council after the International Atomic Energy Agency (IAEA) cited Iran for safeguards failures. During this initial phase, the United States declined to participate in direct diplomacy. The diplomatic framework subsequently expanded to include China and Russia, both of which had established strategic relationships with Iran. Historically, after Iran reinstated its nuclear program in the late 1980s, it had relied on nuclear-related assistance and bilateral agreements with China (signed in 1990), Pakistan (signed in 1992), Russia (signed in 1992 and 1995), and the clandestine procurement network of A.Q. Khan.

By integrating these critical supplier and mediator nations into a unified negotiating bloc, the P5+1 successfully established a cohesive international sanctions framework that eventually compelled Iran to negotiate the JCPOA in 2015 . The inclusion of the permanent members of the United Nations Security Council allowed the treaty to be formalized under international law via United Nations Security Council Resolution 2231, which created a binding global framework for the structured lifting and potential reimposition of multilateral sanctions.

The Technical Verification Mandate: Inspectors, Budgets, and Safeguards

The responsibility for verifying and monitoring Iran’s implementation of its nuclear-related commitments under the JCPOA was assigned to the IAEA, an autonomous international organization that administers global safeguards to prevent the diversion of nuclear materials for military applications. Within the IAEA, the physical execution of this mandate was directed by the personnel of the Department of Safeguards. These operations were conducted by highly trained, designated international safeguards inspectors who were formally approved by both the IAEA Board of Governors and the Iranian government.

To support this unprecedented verification mission, the IAEA had to secure significant human, technical, and financial resources. The agency estimated that it required approximately $10 million per year for a 15-year period in additional funding above its regular safeguards budget to execute the specific monitoring tasks mandated by the JCPOA. To fund this expansion, the IAEA proposed integrating roughly $5.7 million for Additional Protocol activities and direct inspector costs into its regular budget, while the remaining $4.4 million was supported through extra-budgetary contributions from member states.

The technical complexity of the JCPOA presented substantial operational and staffing challenges for the agency. The transfer of highly experienced, senior safeguards inspectors to the intensive Iran monitoring program threatened to create personnel shortages in safeguards programs in other countries. To mitigate these human resource constraints, the IAEA utilized cost-free experts provided by member states and shifted to advanced remote monitoring technologies to maintain verification continuity without depleting its global inspection capabilities.

During the peak implementation of the agreement, the IAEA maintained an extensive physical footprint in Iran, deploying approximately 124 designated inspectors. These inspectors spent roughly 3,000 days in the field annually, took hundreds of environmental swipe samples, and placed approximately 2,000 tamper-proof seals on nuclear materials and dual-use equipment. The legal authority for these activities was derived from Iran’s Comprehensive Safeguards Agreement combined with its provisional application of the IAEA Additional Protocol. This framework granted inspectors expanded access to both declared nuclear sites and undeclared locations where suspicious activities were indicated, in some cases requiring Iran to provide access within 24 hours to resolve compliance questions.

Historical Audit of Iranian Compliance (2016–2018)

Between the formal arrival of “Implementation Day” on January 16, 2016, and the unilateral withdrawal of the United States from the pact on May 8, 2018, the official consensus of international monitors, backed by exhaustive technical data, was that Iran was consistently adhering to its JCPOA commitments. During this period, the IAEA issued more than a dozen consecutive quarterly reports confirming that Iran was operating within the strict limits established by the treaty.

This compliance record was repeatedly validated by senior national security officials and intelligence assessments within the United States and among its allies. In its April 2018 formal report to Congress, the U.S. Department of State declared that Iran was “transparently, verifiably, and fully implementing” its treaty commitments. This was supported by Congressional testimony from Secretary of Defense James Mattis, who stated he fundamentally believed Iran was compliant, and Chairman of the Joint Chiefs of Staff General Joseph Dunford, who warned that a unilateral U.S. withdrawal would damage international diplomatic credibility. Furthermore, U.S. Director of National Intelligence Daniel Coats confirmed that the JCPOA had successfully extended Iran’s nuclear “breakout time”—the duration required to accumulate enough fissile material for a single weapon—from a few months to approximately one year.

Under this compliant framework, Iran made significant physical concessions to limit its nuclear infrastructure:

• Enrichment Caps: Iran restricted its uranium enrichment level to a maximum of 3.67 percent $^{235}\text{U}$, which is the standard threshold for civilian medical and research reactors and far below the 90 percent enrichment required for a nuclear weapon.
• Stockpile Reductions: Iran reduced its low-enriched uranium stockpile by 98 percent, keeping its total domestic inventory below the mandated cap of 300 kilograms of uranium hexafluoride, which is equivalent to 202 kilograms of elemental uranium.
• Centrifuge Reductions: Iran dismantled over 13,000 centrifuges, placing them in monitored storage and operating no more than 5,060 first-generation IR-1 machines at the Natanz facility for a ten-year period.
• Fordow and Arak Reconfiguration: Iran ceased all enrichment at its underground Fordow facility, reconfiguring it into a civil research center. Additionally, the core of the heavy-water research reactor at Arak was removed and filled with concrete, and the facility was structurally redesigned with British and Chinese assistance to prevent it from producing weapons-grade plutonium.

Despite the overall record of compliance, critics of the agreement pointed to minor technical anomalies to argue that Iran was exploiting ambiguities in the text. The most prominent of these disputes concerned the 130-metric-ton cap on domestic heavy-water stockpiles. On two separate occasions in 2016 (February and November), the IAEA reported that Iran’s domestic stock had slightly exceeded the limit, reaching 130.9 and 130.1 metric tons respectively. Iran resolved both issues within weeks by shipping the excess heavy water to storage facilities in Oman, from where it was sold to foreign buyers.

While supporters of the deal viewed this as a rapid and compliant remedy, critics such as David Albright of the Institute for Science and International Security argued that the “Oman loophole” was an unauthorized exemption sanctioned by the treaty’s coordinating body, the Joint Commission, under INFCIRC/907. This commission also approved narrow exemptions that allowed Iran to briefly exceed its 300-kilogram low-enriched uranium limit and maintain 19 “hot cells” exceeding standard size restrictions.

Following the U.S. withdrawal and the imposition of unilateral secondary sanctions under the “maximum pressure” campaign, the JCPOA unraveled in a step-by-step sequence . Iran maintained compliance for a full year before beginning to gradually exceed the treaty’s limits in May 2019, ultimately suspending all IAEA enhanced monitoring access by February 2021 . This unravelling eventually culminated in August 2025 when France, Germany, and the United Kingdom triggered the treaty’s “snapback” mechanism, resulting in the formal reimposition of multilateral United Nations sanctions on September 28, 2025, and contributing to the severe regional and energy disruptions of early 2026 .

Deconstructing the “Pallets of Cash” and Foreign Asset Claims

During and after his presidency, Donald Trump repeatedly asserted that the Obama administration had gifted Iran $150 billion in taxpayer funds as part of the JCPOA, including a clandestine transfer of $1.8 billion (or $1.7 billion) in physical currency flown directly into Tehran on cargo aircraft. This narrative conflated two distinct financial issues, mischaracterizing both the mechanism of international sanctions relief and a long-standing legal settlement adjudicated under international law.

The $150 Billion Foreign Asset Dispute

The claim that the United States government transferred $150 billion of American taxpayer money to Iran is inaccurate. The JCPOA did not involve any direct financial payments, gifts, or signing bonuses from the U.S. Treasury to Tehran. Instead, the financial relief consisted of unfreezing Iran’s own foreign currency reserves, which had been locked in commercial and central banks overseas by the international sanctions regime.

Furthermore, the $150 billion figure represents an inflated, upper-bound estimate of Iran’s total global assets. In congressional testimony, Treasury Secretary Jacob Lew and acting Under Secretary Adam Szubin clarified that while Iran’s total frozen assets nominally exceeded $100 billion, a large portion was entirely illiquid. Approximately $50 billion to $70 billion was tied up in outstanding loans to Iranian state entities, lent to the Central Bank of Syria, or committed to long-term joint infrastructure and petrochemical ventures with China. The actual volume of usable, liquid foreign assets that Iran was able to access and repatriate was approximately $50 billion to $56 billion.

The Hague Claims Tribunal and the $1.7 Billion Settlement

The physical transfer of currency to Tehran refers to a separate, legally binding arbitration settlement of $1.7 billion finalized in January 2016. This payment was not an element of the JCPOA negotiations; rather, it resolved a 37-year-old legal dispute adjudicated by the Iran-United States Claims Tribunal (IUSCT) in The Hague.

The dispute originated prior to the 1979 Islamic Revolution, when the pro-Western regime of the Shah deposited $400 million into a U.S. Foreign Military Sales trust fund to purchase advanced fighter jets and military hardware. Following the revolution and the subsequent hostage crisis, diplomatic relations were severed, the military equipment was never delivered, and the U.S. government froze the $400 million account. In 1981, under the Algiers Accords, the IUSCT was established to systematically resolve outstanding state-to-state and private claims. Over three decades, the tribunal successfully settled thousands of cases, awarding more than $2.5 billion to U.S. claimants and $1 billion to Iranian claimants.

To implement the Algiers Accords, President Ronald Reagan issued an executive order in 1981 suspending outstanding private claims against Iran in U.S. courts and transferring them to the international tribunal, a measure that was urgently upheld by the U.S. Supreme Court in the landmark case Dames & Moore v. Regan. In an 8–1 decision written by Justice William Rehnquist, the Court ruled that while the International Emergency Economic Powers Act did not explicitly authorize the presidential suspension of lawsuits, a long history of congressional acquiescence in executive claims settlements validated the action.

By late 2015, the remaining state-to-state claim regarding the pre-1979 military trust fund was nearing a final ruling by the tribunal. Legal advisors within the U.S. Department of State determined that the United States faced an acute litigation risk. The tribunal was prepared to rule against the United States and order the return of the $400 million principal plus 37 years of compound interest, which would have obligated U.S. taxpayers to a much larger award. U.S. diplomats negotiated the interest down to a fixed compromise of $1.3 billion, capping the total taxpayer exposure at $1.7 billion.

Logistical Mechanics of the Cash Shipment

To satisfy the $400 million principal of this legally binding settlement, the Obama administration procured Swiss francs, euros, and other foreign currencies from the Swiss and Dutch central banks. This physical cache was transported to Tehran on an unmarked cargo aircraft on January 17, 2016. Crucially, the remaining $1.3 billion of interest was not crammed into cargo planes; it was settled subsequently through standard financial channels.

The decision to ship physical currency was not a covert measure to bypass federal oversight; it was legally required by the stringency of the United States’ own sanctions architecture. Because the U.S. maintained strict primary sanctions that prohibited American financial institutions from conducting transactions with Iran or clearing transactions in U.S. dollars, it was legally impossible for the Federal Reserve to execute an electronic wire transfer to the Central Bank of Iran. Physical non-U.S. currency was the only legally compliant mechanism available to fulfill the settlement.

The controversy surrounding this transaction arose because the cash transfer and the announcement of the tribunal settlement coincided precisely with the release of five detained American citizens in a separately negotiated prisoner swap. While the administration maintained that the prisoner swap and the legal arbitration were handled on independent diplomatic tracks, officials later acknowledged that they withheld the physical departure of the cargo plane from Switzerland until the American detainees were safely out of Iranian airspace. This overlap of timelines created negative political optics, allowing critics to characterize the legal settlement as a de facto ransom payment.

Fiscal and Macroeconomic Realities of Sanctions Relief

The implementation of the JCPOA provided immediate, substantial economic benefits to the Iranian economy by lifting the multilateral embargoes that had severely restricted its trade and financial sectors. Prior to 2016, sanctions had halved Iran’s crude oil exports, dragging production down to 2.8 million barrels per day (bpd) and severely reducing the state’s fiscal revenues.

Upon the lifting of these restrictions, Iran’s crude oil production rebounded rapidly, rising to an average of 3.1 million bpd in 2016 and reaching 3.6 to 3.8 million bpd by 2017. Oil exports surged by over 1 million bpd within a single year, reclaiming their pre-sanctions baseline of approximately 2.4 million bpd. This recovery in the hydrocarbon sector acted as a massive terms-of-trade shock, driving a powerful macroeconomic recovery.