Donald Trump has announced that he will pull the US out of the Iran nuclear deal, a decision that has reverberated around the world.

It is important to note that in February, the International Atomic Energy Agency (IAEA) said Iran was in compliance with the deal, something that was welcomed by the various parties, including the US.

So the president's decision to pull the US out of the Joint Comprehensive Plan of Action (JCPOA), which was brokered by seven parties and signed in 2015, it would place everyone in uncharted territory. Despite that, some things are already clear.

What are the options for Donald Trump?

Under the terms of the deal, the US has issued waivers to longstanding sanctions imposed long before Mr Trump came to office that have sought to punish Iran for its nuclear programme. Iran, in turn, restricted its programme and allowed more international inspections.

The US president must decide whether to renew the waivers that eased one basket of sanctions: those on Iran’s central bank, intended to hit Iranian oil exports, and which would force global companies to reduce their purchases of oil from Iran. The Associated Press said another basket of sanctions’ waivers are up for renewal on July 11, and three of those focus on more than 400 specific Iranian companies, individuals and business sectors.

One of Mr Trump’s options, being called “the nuclear option” by some experts, would re-impose all the sanctions at once. That would put the US in immediate violation of the deal’s terms, which say sanctions remain lifted as long as Iran is complying with its terms. Almost everyone, including US Secretary of State Mike Pompeo, has said Iran is complying. The most recent IAEA compliance report was in February

What is Mr Trump’s motivation?

Mr Trump has never hidden his distaste for the Iran nuclear deal, which he has referred to as the “worst deal ever”. At the same time, he has expressed a willingness to work to improve the arrangement. He has particularly objected the accord’s sunset clause, which allows Iran to resume part of its nuclear programme after 2025.

While Mr Trump may have concerns about the deal, many observers believe he is being put under pressure from hawks in his party who never liked the deal and, figures such as Israeli leader Benjamin Netanyahu, who considers Iran an existential threat. Last week, the prime minister of the only country in Middle East generally believed to already possess nuclear weapons, claimed Tehran was in breach of the 2015 deal and had been hiding its true intentions from the other signatories to the deal.

It also seems Mr Trump likes the idea of being able to turn to his core supporters and say: “Look, I’ve delivered on another promise”.

Yet, there is concern that Mr Trump has not thought through where this will lead. In a conference call for the media, organised by Diplomacy First, a group of former diplomats and officials seeking to retain US participation in the deal, Jake Sullivan, former Deputy Assistant to Barack Obama and a senior advisor during the negotiations, said: “What will be immediately obvious after May 12th is that President Trump is throwing the United States and the Iran deal into a new nuclear crisis, essentially to cater to his political base, and neither the president nor his administration appear to have any strategy or plan for what comes next.”

Iran president Rouhani: US ending nuclear deal will be "historic regret"

What about Europe?

Senior figures from Britain, France, Germany and other members of the EU have urged Mr Trump to stick with the deal, saying it is the best way to retain a handle on what Iran is doing and ensure inspection teams have access. Both French president Emmanuel Macron and British Foreign Secretary Boris Johnson have suggested the deal has sufficient elasticity to be strengthened and tweaked to satisfy Mr Trump’s concerns.

Mr Johnson appeared on one of the US president’s favourite cable shows, Fox and Friends, to urge the him to keep with it. “We have to be tougher on Iran and we've got to fix the flaws in the deal,” said Mr Johnson.

He said the agreement can help avoid a nuclear arms race, one that would also include Saudi Arabia and other nations in the Middle East. He added: “Plan B does not seem, to me, to be particularly well developed at this stage.”

On Monday German Foreign Minister Heiko Maas said it was clear that the agreement had made the world more secure.

“We don't think there is any justifiable reason to pull out of this agreement and we continue to make the case for it to our American friends,“ Mr Maas said during a joint news conference with visiting French Foreign Minister Jean-Yves Le Drian. “We'll deal with the [US] decision but like Jean-Yves said, we want to adhere to this agreement.”

Yet the AP pointed out that while the EU has said it will remain with the deal even if the US pulls out, it might not matter much given that the global financial system is so interconnected and tied to the US. It would be almost impossible for anyone anywhere in the world to continue their business with Iran without risk of violating US sanctions.

Iran protests – in pictures Show all 11 1 /11 Iran protests – in pictures Iran protests – in pictures University students at an anti-government protest inside Tehran University, 30 December 2017 AP Iran protests – in pictures A university student at a protest inside Tehran University while a smoke grenade is thrown by anti-riot Iranian police, 30 December 2017 AP Iran protests – in pictures University students at a protest inside Tehran University, 30 December 2017 AP Iran protests – in pictures University students run away from the police during an anti-government protest inside Tehran University, 30 December 2017 AP Iran protests – in pictures An image grab taken from a handout video released by Iran's Mehr News agency reportedly shows a group of men pulling at a fence in a street in Tehran, 30 December 2017 AFP/Getty Iran protests – in pictures Demonstrators gather to protest in Tehran, 30 December 2017 AP Iran protests – in pictures Iranians chant slogans as they march in support of the government near the Imam Khomeini grand mosque in Tehran, 30 December 2017 AFP/Getty Iran protests – in pictures Iranians chant slogans as they march in support of the government near the Imam Khomeini grand mosque in Tehran, December 30 2017 Iran protests – in pictures Iranian clerics take part during a state-organized rally against anti-government protests in the country, in the holy city of Qom, south west Iran, 3 January 2018 EPA Iran protests – in pictures In this photo provided by the Iranian Students' News Agency, a clergyman takes a picture of a pro-government demonstration in the southwestern city of Ahvaz, Iran, 3 January 2018 ISNA via AP Iran protests – in pictures Pro-government demonstrators gather at the Massoumeh shrine in Iran's holy city of Qom, some 130 kilometres south of Tehran, 3 January 2018 AFP/Getty

What will Iran do?

Iran wants the US to remain in the deal, which has helped improve the country’s economy and strengthened the hand of relative political moderates such as the nation’s president, Hassan Rouhani. On Monday, Mr Rouhani said the US would regret any decision to leave the deal and vowed to resist US pressure.

“If they want to make sure that we are not after a nuclear bomb, we have said repeatedly that we are not and we will not be,” he said in a televised speech, according to Reuters. “But if they want to weaken Iran and limit its influence whether in the region or globally, Iran will fiercely resist.”

Observers believe the hand of hardliners would be strengthened if the US pulled out. Tehran has already said it would step up its nuclear activities if sanctions were to be reimposed. It would also increase its testing of missiles and support for militant groups.

“We are not worried about America's cruel decisions...We are prepared for all scenarios and no change will occur in our lives next week,” said Mr Rouhani. “If we can get what we want from a deal without America, then Iran will continue to remain committed to the deal. But if not, Tehran will continue its own path.”

The AP highlighted that while Iran would still technically remain obligated to permit inspections as a signatory of the Nuclear Nonproliferation Treaty, it would no longer be bound by the more rigorous inspections regime by the IAEA that it agreed to in the deal.

That regime included the so-called Additional Protocol, which expanded the IAEA’s access to sites in Iran, including giving inspectors insight into all parts of the nuclear fuel cycle, access on short notice to all buildings at an acknowledged nuclear site, and the right to obtain samples from military sites.

What would North Korea make of all this?

Some observers believe it is possible that Mr Trump will recertify the deal in order to persuade North Korea to carry out its stated wish to hold a summit with the US president.

Alexandra Bell, a senior policy director at the Washington-based Centre for Arms Control and Non-Proliferation, told The Independent that if the US reimposed sanctions it would be in violation of the deal it signed three years earlier.

“We lose our credibility as someone who can he trusted,” she said of such a scenario. “Why would North Korea sign any sort of deal after that?”

What is Mr Trump most likely to do?

One thing the US president has proven since he entered the White House, is that it can be a hopeless task to try and guess his actions. Mr Sullivan, the former Obama advisor, said last week “all signs right now point to the administration deciding not to issue the waivers that are coming up for renewal on May 12th”.

But things are not necessarily so black and white. There are at least three possible steps Mr Trump could take.

Firstly, he could sign the waiver again as he has done every four months since taking office, but add a series of demands and caveats. This would keep the deal alive and allow those European nations who have said they will work to fix the deal, to try to do so.

Secondly, he could refuse to sign the waiver but not push immediately for the reintroduction of sanctions.

Anshel Pfeffer of Haartez, wrote: “The sanctions that target Iran’s central bank, and are mainly aimed at hampering its international oil deals, do not come into effect for another 180 days - effectively giving the administration and the other signatories five more months to search for a compromise.

“At this point, the Europeans will be scrambling in both directions: To try to find a solution that could still make Trump backtrack and sign the waivers, better late than never; and, at the same time, prevent the Iranians from pulling out of the JCPOA.”

The third scenario, the one that Iran, Europe and the other signatories of the deal want to avoid is, Mr Trump refusing to sign the waiver and pushing ahead with new US sanctions, putting Washington at sharp odds with its supposed allies in Europe.