Since 1957, the United States played a crucial role in the establishment of Iran’s nuclear programme.

In December 1953, US President Dwight Eisenhower stood before the United Nations to deliver his “Atoms for Peace” speech.

In his address, he detailed a policy seeking to provide technology and educational resources for friendly nations interested in developing a nuclear programme for civilian purposes, including energy production.

As an ally of the United States, Iran became one of the first beneficiaries of the programme.

In 1957, the two countries signed an agreement in Washington, DC, formalising their cooperation in order for Tehran to begin developing atomic energy for civilian purposes.

By 1974, US President Richard Nixon had sent experts to Tehran to help the country build its nuclear reactors. The US also helped train the first batch of Iran’s nuclear scientists at Massachusetts Institute of Technology. Some of them would eventually help modernise Iran’s nuclear reactors.

Here’s a brief history of Iran’s nuclear programme, and its storied relationship with the United States.

Iran’s Shah Mohammad Reza Pahlavi and US President Eisenhower drive through cheering crowds in Tehran in 1959 [File: AP]

Iran and the United States sign an agreement concerning civil uses of atomic energy. It is part of the “Atoms for Peace” policy declared by Eisenhower in 1953.

Shah Mohammad Reza Pahlavi, under whose rule Iran was a close ally of the US and the UK, establishes the Tehran Nuclear Research Center.

The US provides Iran with its first research nuclear reactor, the Tehran Research Reactor, a five-megawatt apparatus that continues to be in operation until today.

Iran ratifies the nuclear Non-Proliferation Treaty (NPT), making its programme subject to International Atomic Energy Agency (IAEA) verification.

Shah Reza Pahlavi announces a plan for Iran to build at least 20 nuclear reactors. Two months later, Nixon sends experts to Tehran to help in the building of the reactors.

A 1968 Iranian newspaper clip says a quarter of Iran’s nuclear scientists were women [Wiki Commons]

Iranian students arrive in the US to train as nuclear scientists at the Massachusetts Institute of Technology. According to the Boston Globe, at least three of the 35 graduates will dedicate their careers building Iran’s nuclear programme.

The shah and Empress Farah leave Iran on January 16, 1979 [File: AP]

At the height of the Iranian Revolution, the shah and his family flee the country. Less than a month later, Ayatollah Khomeini returns to Iran after 14 years in exile. Following the revolution, Iran’s nuclear energy programme is temporarily halted.

Iranian students storm the US embassy in Iran and take diplomats hostage, leading to a diplomatic breach that continues up to this day. The hostages are released 444 days later on January 21, 1981 at the beginning of US President Ronald Reagan’s term in office.

An Iraqi soldier on guard in the Iranian village of Khosrawi in October 1980 [File: AP]

With US backing, Iraq launches a military attack against Iran, igniting the eight-year Iran-Iraq War, during which Iran will feel an energy crunch. As the war with Iraq rages on, Iran resumes its interest in a national nuclear programme.

Following the first US-led Gulf War against Iraq’s Saddam Hussein, Iran begins to dedicate funds to speed up its research and development of nuclear power. In 1995, it signs several deals with Russia for the development of its nuclear programme.

The Arak nuclear complex is comprised of a heavy water experimental reactor [Wiki Commons]

The administration of US President George W Bush accuses Iran of pursuing a secret nuclear weapons plan. Months earlier, the exiled opposition National Council of Resistance of Iran will report the existence of a uranium enrichment facility at Natanz and a heavy water plant at Arak.

An IAEA report on the inspections says that Iran has failed to comply with the NPT. More than a year later, Iran promises European Union (EU) negotiators that it will suspend all nuclear fuel processing and reprocessing work.

In his speech before the UN in 2012, Ahmadinejad defended Iran’s nuclear programme [File: AP]

Mahmoud Ahmadinejad, mayor of Tehran, is elected president. Months later, the IAEA will report that Iran has resumed uranium conversion at the Isfahan nuclear research facility.

Iran resumes nuclear fuel research at the Natanz enrichment plant after breaking the United Nations (UN) seals on the facility, prompting the IAEA to report Iran to the UN Security Council.

The UN Security Council votes for sanctions and gives Iran a 60-day deadline to suspend enrichment. Iran calls the resolution illegal.

The UN Security Council unanimously approves further financial and weapons sanctions against Iran over its uranium-enrichment activities, which Tehran says are for peaceful purposes.

Iran Revolutionary Guard Corps is an elite force under the direct command of the Supreme Leader [File: AP]

The US imposes new sanctions on Iran and accuses the elite Islamic Revolutionary Guard Corps of distributing weapons of mass destruction. A month later, China, France, Russia, the UK, the US and Germany (P5+1, or “the group of six”) will agree to push ahead with a third round of tougher sanctions.

A US National Intelligence Estimate says Iran halted its attempts to build a nuclear bomb in 2003. It also says with “moderate confidence” that the programme has not resumed as of mid-2007.

A quarterly IAEA report says Iran now has 7,231 centrifuge enrichment machines installed, a 25 percent increase in potential capacity since March. Two months later, the IAEA will say that Iran has slightly reduced the scale of its uranium enrichment, while also raising the number of installed centrifuge machines by some 1,000, to 8,308.

The six world powers – P5+1 – and Iran launch a new round of negotiations in Turkey’s biggest city, Istanbul.

Hassan Rouhani, the former chief nuclear negotiator, is declared the winner of Iran’s presidential elections.

Rouhani has an historic phone call with US President Barack Obama.

At least two years of negotiations between Iran and the world powers yielded a deal in 2015 [File: AP]

Secret US-Iran talks are revealed. Iran agrees to curb certain nuclear activities and accept enhanced IAEA monitoring. In return, minor sanctions are lifted, and Iran is promised that no new sanctions will be imposed. The deal is considered temporary until a new, broader agreement is reached.

Israel’s Prime Minister Benjamin Netanyahu launches a last-ditch effort to stop the Iran nuclear deal by delivering a speech before the US Congress.

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Iran and the six world powers sign the nuclear deal, formally known as the Joint Comprehensive Plan of Action (JCPOA). The accord ends nearly 12 years of a nuclear standoff between Iran and Western powers led by the US. In exchange of Iran giving up its nuclear weapons programme, international sanctions are lifted.

Ehud Barak, former Israeli prime minister and defence minister, says Netanyahu wanted to attack Iran’s nuclear facilities in 2010 and 2011.

Since the signing of the Iran deal, the IAEA has verified Iran’s compliance 10 times [File: AP]

International sanctions against Iran are lifted after the IAEA’s Yukiya Amano says that Tehran has complied with its side of the July 2015 agreement.

Donald Trump is elected president of the US. During his campaign, Trump repeatedly vowed to withdraw from the Iran nuclear pact, calling it the “worst” deal ever.

Supporters of Rouhani attend a street campaign ahead of his re-election in May 2017 [File: AP]

Rouhani is re-elected as president. During his first term, Rouhani vowed that economic sanctions in Iran will be lifted.

Trump “decertifies” the 2015 Iran nuclear deal, saying Tehran is not living up to the spirit of the accord.

Trump waives US sanctions against Iran for the “last time”. He says that if his demands to change the deal are not met within 120 days, the US will withdraw from the deal on May 12.

IAEA’s Yukiya Amano says Iran has continued to implement its nuclear-related commitments under the JCPOA. It is the 10th IAEA report certifying Iran’s compliance with the deal.

Experts said there was nothing new to what Netanyahu said in his speech [File: Reuters]

Netanyahu delivers a speech saying that Iran pursued a “secret nuclear programme”, but experts say there was nothing new to what was said.

The EU’s Federica Mogherini and other US allies say that Iran continues to abide by the JCPOA since it was signed in 2015.

Experts also say Netanyahu’s speech proves that inspections are necessary, and that ending the deal can lead to an end of regular inspections.

Trump announces that the United States is withdrawing from the Iran nuclear deal, directing his administration to re-impose sanctions.

In response, Rouhani says Tehran will bypass Washington and negotiate with the other signatories of the deal.

US President Donald Trump’s first round of sanctions against Iran takes effect.

Trump’s sanctions were designed in two phases, based on the 90-day and 180-day wind-down periods set by the US Department of Treasury, counting from the May 8 announcement.

The first phase targeted aviation and auto industry, as well as its currency and the sale of Iranian products such as carpets, caviar and pistachios.

Second round of US sanctions targeting Iran’s oil and gas industry, as well as its banking, is reimposed.

Iran has vowed to defy the sanctions and said it will continue to trade energy, which is the source of up to 80 percent of the country’s export revenues.