The Iran Conflict: Nuclear, Regional and Diplomatic

**The 1979 revolution and the founding constraint.** The modern Iran file begins with the Islamic Revolution of 1979. The fall of Shah Mohammad Reza Pahlavi, the return from exile of Ayatollah Ruhollah Khomeini, and the founding of the Islamic Republic ended a Cold War alignment that had treated Iran as a pillar of Western security in the Gulf. The hostage crisis at the US embassy in Tehran (November 1979 – January 1981) set the diplomatic baseline: the United States and the Islamic Republic have had no formal diplomatic relations since, conducted through Swiss intermediaries.

**The Iran–Iraq war.** From September 1980 to August 1988 Iran and Iraq fought a war that defined the regional security calculus for a generation. Iraqi forces invaded in 1980; the war became a long grinding conflict that included extensive Iraqi use of chemical weapons against Iranian forces and Kurdish civilians. The Iran–Iraq war shaped Iranian military doctrine — including the prioritisation of asymmetric capabilities and proxy networks — and informed the Islamic Republic's conviction that it could not rely on outside guarantors for its security.

**The nuclear file: origins to the JCPOA.** Iran's nuclear programme dates to the Shah era. Civilian cooperation continued in attenuated form after the revolution, but in August 2002 the National Council of Resistance of Iran, an opposition group, publicly revealed undeclared enrichment facilities at Natanz and a heavy-water reactor under construction at Arak. The revelations triggered the modern international file, with the International Atomic Energy Agency (IAEA) demanding access and the United Nations Security Council eventually imposing multiple sanctions resolutions between 2006 and 2010.

Negotiations between Iran and the P5+1 (the five permanent UNSC members plus Germany) intensified after the election of President Hassan Rouhani in 2013. The Joint Comprehensive Plan of Action (JCPOA), agreed in Vienna on 14 July 2015 and endorsed by UNSC Resolution 2231, capped Iranian enrichment at 3.67 % uranium-235, limited the stockpile of enriched material, required modifications to the Arak reactor, and established intrusive IAEA monitoring — in exchange for the lifting of nuclear-related UN, US, and EU sanctions. The IAEA verified Iranian compliance through multiple reports between 2016 and 2018.

**The US withdrawal and "maximum pressure".** On 8 May 2018 the first Trump administration withdrew from the JCPOA and reimposed the US nuclear sanctions, with secondary sanctions targeting foreign firms doing business with Iran. The European parties to the JCPOA (France, Germany, UK) attempted to preserve the deal through a special-purpose vehicle (INSTEX) for non-dollar trade; the mechanism was operationally limited. Iran responded over 2019 by progressively breaching the JCPOA's enrichment cap, accumulating stockpile, enriching to higher levels, and limiting IAEA access.

**The Soleimani killing and after.** On 3 January 2020 a US drone strike at Baghdad airport killed Qassem Soleimani, commander of the Quds Force — the external arm of the Islamic Revolutionary Guard Corps. The strike represented the most direct US targeting of an Iranian state actor since 1979. Iran retaliated days later with ballistic missile strikes on US bases in Iraq, deliberately calibrated to avoid US casualties. The same period saw Iranian air defences shoot down a Ukrainian International Airlines flight near Tehran, killing all 176 aboard — an event Iran initially denied and then acknowledged.

**The 2022 Mahsa Amini protests.** The death of Mahsa Amini in the custody of Iran's morality police in September 2022 triggered the largest sustained anti-government protests of the Islamic Republic's history, organised under the banner *Woman, Life, Freedom*. Hundreds of protesters were killed and thousands detained over months. The protests did not topple the government and tapered through 2023, but they shifted the internal political baseline and the regime's tolerance for public dissent.

**The October 2023 escalation and its consequences.** The Hamas attack on Israel of 7 October 2023 reshaped the regional file. Hezbollah opened a northern front against Israel from southern Lebanon the next day. Iranian-backed groups in Iraq, Syria, and Yemen activated. The Houthis began missile and drone attacks on shipping in the Red Sea. For the first time in the file's history, Iran and Israel exchanged direct strikes on each other's territory: in April 2024 Iran launched a coordinated drone-and-missile attack on Israel (largely intercepted with allied support); in October 2024 Israel struck Iranian air-defence sites; and through 2024 a series of Israeli operations decimated Hezbollah's senior leadership, including the killing of Secretary-General Hassan Nasrallah on 27 September 2024.

**The fall of Assad and the land bridge.** The collapse of the Assad regime in Syria in early December 2024, following an offensive led by Hayʿat Tahrir al-Sham, removed a core Iranian ally and severed the land corridor Tehran had used to resupply Hezbollah. The strategic consequence — independently of who governs Damascus next — is that the Islamic Republic's regional posture is structurally weaker than it has been at any point since the 1980s. The "axis of resistance" as constructed over four decades has been materially degraded.

**The nuclear file today.** Through 2024 and into 2025 the IAEA has continued to report enrichment activity at levels well above the JCPOA cap, with stockpile sizes Iran could in principle further enrich. The agency's monitoring access remains restricted relative to the JCPOA period. Whether Iran has made a political decision to weaponise — a separate question from technical capacity — is contested and unknown to outside observers. The *Current situation* section above carries the present state of negotiations.

**Distinguishing what is known.** This file generates more confident-sounding speculation than almost any in current geopolitics. The agreed factual baseline is narrower than it often appears in commentary: Iran enriches uranium at levels above the JCPOA cap (confirmed by IAEA); the regional proxy network has been materially weakened since late 2024 (confirmed by open-source reporting and acknowledged on Iranian and Israeli sides); diplomatic channels exist and have been used (confirmed in public statements). What is *not* known with the certainty it is often asserted: Iran's exact stockpile of high-enriched material; the state of any covert programme elements; the durability of recent ceasefires; the internal Iranian political balance and succession trajectory.

**The European dimension.** The EU3 (France, Germany, UK) remain formally party to the JCPOA. The European External Action Service has historically convened Iran talks in Brussels. As US bilateral channels have narrowed, the EU's residual diplomatic role has become more — not less — important. Belgian compliance officers at Antwerp-port-based firms, Euroclear, and major banks navigate the daily friction between US secondary sanctions and EU regulation.