House of Commons Research Briefing - Israel-Iran 2025:
Developments in Iran’s nuclear programme and military action

This UK House of Commons Research Briefing, Israel-Iran 2025: Developments in Iran’s nuclear program and military action, published on June 17, 2025, examines the sharp escalation between Israel and Iran following Israel’s June 2025 pre-emptive strikes on Iranian nuclear sites, scientists, and military leaders. The report details Iran’s growing stockpile of enriched uranium far beyond JCPOA limits, its near-zero breakout time to weapons-grade material, and the military confrontation that ensued, including Iranian ballistic missile attacks and Houthi strikes on Israel. The briefing also surveys the international response, highlighting calls for de-escalation, the collapse of diplomatic talks, and divergent reactions from Western powers, Russia, and China.

The following is an executive summary. For the full report, click here. 

On 13 June 2025, Israel launched a series of attacks against Iran’s nuclear facilities, its nuclear scientists, and senior commanders in the Islamic Revolutionary Guard Corps. Israel said the attacks were “pre-emptive” as Iran was “closer than ever to obtaining a nuclear weapon”. Iran says that its nuclear programme is peaceful and that it has no plans to develop nuclear weapons. Iran has responded with ballistic missile strikes on Israel.

There have been widespread international calls for both parties to de-escalate.  

Status of Iran’s nuclear programme

Since 2019, Iran is considered to have been incrementally violating the terms of the Joint Comprehensive Plan of Action (JCPOA, commonly referred to as the ‘Iran nuclear deal’), which was agreed between Iran, the UK, China, France, Russia, the US, and Germany in 2015. Under the terms of that deal, Iran accepted limits on its nuclear programme in exchange for sanctions relief.

Iran is currently enriching uranium to 60%, which is significantly beyond the 3.67% permitted under the JCPOA and far beyond enrichments levels considered necessary for civilian purposes. Weapons-grade uranium is enriched to 90%. Iran’s overall stockpile of enriched uranium (at varying degrees of enrichment) is currently more than 40 times that permitted under the JCPOA, and it continues to expand its enrichment capabilities with the installation of additional, more advanced, centrifuges. The International Atomic Energy Agency (IAEA) has noted that while enrichment is not forbidden in and of itself, “the fact that Iran is the only non-nuclear-weapon State in the world that is producing and accumulating uranium enriched to 60% remains a matter of serious concern” (PDF).

Iran’s nuclear ‘breakout’ time (the time taken to develop enough fissile material for a nuclear weapon) is estimated to be almost zero (PDF). The IAEA considers Iran to have enough nuclear material for nine nuclear weapons if further enrichment to 90% is achieved. However, ‘breakout’ time does not account for the technological capability and time required to successfully construct a deliverable nuclear weapon (weaponisation) which, in 2022, was estimated by the International Institute for Strategic Studies to be one to two years. 

In June 2025, the IAEA Board of Governors adopted a resolution which, for the first time since 2005, formally found Iran to be non-compliant with its nuclear safeguards obligations (PDF). In response to the IAEA resolution, which Iran said was politically motivated, it announced a number of measures intended to accelerate its nuclear programme.

Progress of talks

Since the end of 2024, Iran has held separate talks on its nuclear programme with the E3 (the UK, France and Germany), in a forum with China and Russia, and in a series of indirect talks with the United States, brokered by Oman. International attention has focused primarily on the five rounds of indirect talks between the US and Iran, which have been held since the beginning of April 2025. A sixth round of talks in Oman on 15 June 2025 was cancelled after Israel launched a series of attacks against Iran’s nuclear facilities and personnel on 13 June 2025.

Israeli military action and Iranian counter strikes

Israel’s military strikes that began on 13 June 2025 have targeted Iran’s nuclear programme, but also its conventional military assets, senior military leaders, and non-military targets.

Attacks on Iran’s nuclear programme have included strikes against Natanz, a main enrichment facility, which has been reported to have suffered significant damage. Parts of the Isfahan nuclear site have also been damaged. Israel reportedly attacked the heavily protected Fordow nuclear site, but no damage has been reported. The IAEA Secretary General criticised the military strikes saying, “nuclear facilities must never be attacked, regardless of the context or circumstances”. Israel has also reportedly killed at least 14 of Iran’s nuclear scientists, some of whom were targeted by car bombs.

Nuclear experts have largely questioned the effectiveness of Israel’s actions in degrading Iran’s nuclear programme.

Israel has also targeted conventional military targets in Iran including its air defences and mobile rocket launchers, and has reportedly killed over 16 senior members of Iran’s military. It has also struck non-military targets such as oil and gas infrastructure and Iran’s state news broadcaster.

Iran initially responded to the Israeli attacks with drones strikes but subsequently launched several waves of ballistic missiles against Israeli cities.

The Iran-backed Houthi armed group, based in Yemen, has also launched missile strikes against Israel, “in coordination” with Iran.

International response

The UK has called for de-escalation, and the Foreign Secretary, David Lammy, has said “no military action can put an end to Iran’s nuclear capabilities”. Both Mr Lammy and the Prime Minister have said that the UK military was not involved in Israel’s strikes on Iran.

The Foreign Commonwealth and Development Office (FCDO) has now advised against all travel to Israel and asked all British citizens in Israel to register their presence with the UK Government. The UK has also strengthened its military presence in the region, including deploying additional RAF aircraft.

The United States has emphasised that it was not involved in Israel’s military strikes, as well as the need for a negotiated settlement. President Trump has warned Iran against any attacks on US military assets or personnel in the region.

European Commission President, Ursula von der Leyen, has also urged de-escalation and a negotiated solution, while saying that “Israel has the right to defend itself” and that “Europe has always been clear: Iran can never acquire a nuclear weapon”.

China and Russia have both condemned Israel’s attacks on Iran, saying they breached international law.

This paper provides an overview of the status of Iran’s nuclear programme and recent developments. It also discusses recent military action between Israel and Iran and responses to this. The briefing does not provide background information on ongoing conflicts and events in the Middle East.

Further information is available in the Commons Library collection: Middle East instability in 2023 and 2025.

Source: “Israel-Iran 2025: Developments in Iran’s nuclear programme and military action,” UK Parliament, (June 17, 2025).