Israel to strike Iran's nuclear facilities? As US pulls staff from Middle East, here's a timeline of Iran's nuclear programme

Amid fears that Israel might conduct a strike on Iran's nuclear facilities, the US on Wednesday (June 11) asked military and other personnel from the Middle East region to leave. This is taking place as there's no progress between Iran and US on negotiations on its nuclear programme.

Israel sees a nuclear-armed Iran as an existential threat. A strike on its nuclear facilities, if it happens, would be aimed at setting Iran's nuclear programme back by decades.

Amid these tense developments, here is a look at Iran's nuclear programme, with particular focus on the enrichment of Uranium required for building a nuclear weapon.

What type of uranium is required for creating a nuclear weapon?

Iran has reportedly stockpiled uranium enriched to 60 per cent of the fissionable U-235 isotope since April 2021. Theoretically, uranium is considered weapons-grade when its isotope U-235 has been enriched to about 90 per cent , which is called highly enriched uranium. As of now, Iran is thought to have enriched Uranium by up to 60 per cent. Again, theoretically, only 20 per cent enriched uranium could be sufficient and is called ‘weapon-usable’. But then, hundreds of kilograms of that material would be required to create a nuclear weapon, which would not be practical.

Iran's nuclear programme timeline

Iran has been enriching uranium for decades, even as it insists that its nuclear programme is for peaceful purposes.

The Iranian nuclear programme started in the 1960s, and progressed to advanced enrichment.

Early years of Iran's nuclear programme

In fact, it is the US which provided Iran with its first research reactor, the TRR. It happened in the 1960s, when relations were better. Under the rule of the Shah of Iran at the time, the country started its nuclear programme for peaceful purposes. The TRR started operation at TNRC in 1967.

In the 1970s, Iran ratified the Non-Proliferation Treaty (NPT).

Iran nuclear programme after the Islamic Revolution

In the initial years following the Islamic Revolution that overthrew the Shah, Iran halted its nuclear programme.

But in subsequent years, the programme was revived, with the expressed intention of using it for peaceful purposes, mainly for agriculture.

But slowly, the acquisition of more uranium, the creation of nuclear facilities, and continuing enrichment amid Middle East tensions, drew the suspicion of the international community.

Iranian nuclear programme became a cause of concern for Israel, which argued in international fora that a weapon, eventually, could target the Jewish nation, which is its arch rival in the region.

Iran increased enrichment in 2000s, drawing criticism and scrutiny

In the early 2000s, dissident groups like the National Council of Resistance of Iran drew global attention to Iran's secretive nuclear programme, including enrichment plants.

This led to a round of negotiations. The West adopted a carrot and stick policy towards Iran, imposing a number of sanctions while also negotiating with Iran to scale down its nuclear ambitions.

Iran nuclear talks: The era of negotiations

In the period of 2003-2004, Iran made agreements with the UK, France, and Germany to suspend enrichment and accept enhanced inspections of its nuclear facilities, mainly the UN watchdog IAEA.

But in the mid-2000s, Iran resumed uranium enrichment activities, including in its key nuclear facility at Natanz.

Iran's nuclear enrichment expansion and US sanctions

In spite of global pressure, Iran continued to gradually enrich uranium, bringing it dangerously close to weapons-grade. The West responded with a number of punitive measures, even as Israel raised alarm at every opportunity to draw attention to the Iranian nuclear programme.

In 2006, the UN Security Council banned providing Iran with equipment for uranium enrichment. This happened after Iran announced enrichment of uranium to 3.6 per cent. Between 2007 and 2010, Iran increased the number of centrifuges and enriched uranium to 20 per cent.

Iran nuclear deal : The JCPOA and restrictions on Iran

Under the US administration of Barack Obama, the US and Western powers successfully reached an agreement with Iran on its nuclear programme in 2015. The Iran nuclear deal, formally known as the Joint Comprehensive Plan of Action (JCPOA), was reached between Iran and the P5+1 - the five permanent members of the UN Security Council - China, France, Russia, the UK, and the US - plus Germany. The deal aimed to limit Iran's nuclear programme in exchange for relief from western sanctions. Iran agreed to further restrictions and inspections on its nuclear facilities.

Under its terms, it was only allowed to possess a certain amount of uranium enriched to 3.67 per cent. The deal went into effect in 2006, and Iran mostly complied with the JCPOA in the 2016-2018 period.

Trump exits Iran deal, and Iran resumes enrichment

In 2018, Donald Trump, in his first term as president, pulled the US out of the Iran nuclear deal, essentially leading to the collapse of the JCPOA. Trump, agreeing with what Israel has been saying all those years, alleged that Iran has violated the deal's terms.

In the 2018-2020 period, Iran resumed its uranium enrichment activities and expanded its stockpile of nuclear material.

In 2021, Iran announced enrichment of up to 60 per cent, which led to alarm in the international community. In the 2021-2025 period, Iran was accused of undermining the terms of the nuclear deal by limiting IAEA access to its data and monitoring equipment.

Iran nuclear negotiations of 2025

Under the new Trump administration, the US resumed negotiations with the Iranian government on its nuclear programme, but talks remained inconclusive. The negotiations were happening amid heightened tensions since the 2023 Hamas attack on Israel, and subsequent Israeli occupation of Gaza and the ongoing war. The war saw Iran supporting anti-Israeli groups like Hamas, Houthis and Hezbollah, and the proxy war between the two countries intensified.

It is in this context that there are now strong speculations that Israel might directly target Iran's nuclear facilities.