Iran: Impacts of June 2025 Israel and US strikes

Armed Israel–Iran conflict, 13 June 2025 to 23 June 2025

From 13 June 2025, Israel launched a series of strikes against Iran’s nuclear program, ballistic missile sites, and energy facilities, stating its aim was to stop Iran developing a nuclear weapon (Iran says it has not been developing a nuclear weapon). In response, Iran launched missiles and drones against Israel. Most of Iran’s missiles and drones against Israel were intercepted.

The United States also conducted strikes on 22 June 2025. In response, Iran launched missiles against a US military base in Qatar. There were no reported American casualties.

The UK was not involved in either Israeli or American military action against Iran.

Casualty numbers are uncertain: The Iranian Health Ministry reports that around 1,062 people were killed (as of 22 July 2025). Many senior Iranian political and military leaders and scientists were killed. In Israel, 29 people were killed (to 13 July 2025).

President Trump’s announced ceasefire came into effect on 24 June 2025.

For information on the attacks and their background, including recent developments in Iran’s nuclear programme, see the Commons Library research briefing Israel-Iran 2025: Developments in Iran’s nuclear programme and military action.

How damaged is Iran’s nuclear programme?

The extent of damage caused to Iran’s nuclear programme is uncertain. A preliminary assessment by US intelligence, which has not been published but which has been cited in the media, suggests that US action may have put back Iran’s nuclear programme by “months”. The Trump administration has criticised the reports and says extensive damage has been caused. A statement by the CIA Director says that new intelligence suggests the facilities are “severely damaged”.

On 23 June, the Director General of the International Atomic Energy Agency (IAEA), which is responsible for monitoring Iran’s nuclear activity, said that “no one […] is in a position to have fully assessed the underground damage at Fordow” (one site targeted by the US) but that “very significant damage is expected to have occurred” due to the military action. He said that Iran retains the industrial capacity and knowledge required to resume enrichment work and that ultimately diplomacy and inspections are required to restrict its programme.

How weakened are Iran’s regional alliances?

Iran has a history of supporting armed and terrorist groups across the Middle East, including in Gaza, Yemen and Lebanon, as a forward-defence mechanism to deter military action against Iran and to establish friendly governments. However, since 2023, and primarily due to Israeli military action, the capacity of many of the groups to mobilise has reduced and, aside from the Houthis in Yemen, groups did not respond militarily to the attacks.

While Iran’s defensive network is weakened, Israel faces challenges to deepening its ties with Arab Gulf states due to their criticism of Israel’s conduct in Gaza and lack of progress on a two-state solution. Turkey, also critical of Israel, has been able to expand its influence in Syria since President Bashar al-Assad, an ally of Iran, left the country in December 2024.

What was the domestic response in Iran?

During the conflict, the Iranian Government arrested around 700 people and at least six people were executed on charges of espionage. The use of the death penalty in Iran in 2024 was already estimated to be its highest since 2015. Among those executed were people who participated in the 2022 Mahsa Amini protests. Access to the internet was also shut down during the conflict.

While US Government and Israeli Government statements suggested regime change in Iran could be an effect of the military strikes, analysis by the Institute for the Study of War that assessed the targets chosen by Israel suggested this was not an operational aim. Nonetheless, media reports suggest that Iranian leaders have been discussing potential successors to the current supreme leader, Ali Khamenei, who is 86. Many senior Iranian leaders were killed in the Israeli action.

What is the outlook and what are the risks?

The US has announced a return to talks with Iran over its nuclear programme, though Iran says the US must first rule out any further military action. It is uncertain what the terms of any agreement will be, Iran having rejected American requests to end all enrichment of nuclear material within Iran. In 2024, there was also domestic debate in Iran on whether to change its nuclear policy and on whether to announce it will develop a nuclear weapon. Analysts argue Iran’s weakened regional position may make this a greater possibility, though this will carry the risk of further military action. Iran has said it will continue to work with the IAEA but says “safety” and “security” reasons may make its nuclear sites hard to investigate at present.

The UK, Germany and France (the E3) have also said they are willing to invoke snapback sanctions against Iran under the 2015 nuclear agreement to ensure it does not develop a nuclear weapon. The power for the E3 to invoke snapback sanctions against Iran expires in October 2025 and August has been set as a potential deadline for sanctions to used. The United States is unable to invoke the sanctions power as it withdrew from the 2015 nuclear agreement under the first Trump administration in 2018. Iran says “tensions could escalate irreversibly” if the snapback sanctions power is used.

During the June 2025 conflict, the UK Government also warned that Iran may seek to respond by taking action in the UK. Canada and the United States have issued similar warnings about the potential for increased Iranian activity abroad. The UK Government is currently drafting legislation to counter state-based threats, including from Iran. Iran says it is willing to discuss “these kinds of misunderstandings” on its actions in the UK.

This research briefing surveys initial assessments of the damage done to Iran’s nuclear programme, the weakened regional power of Iran, how the government has responded within Iran, and outlook and risks.