The nuclear deal between Iran and the 5 +1 world powers (US, Russia, Britain, China, France and Germany) is historic and a victory for patient diplomacy. It may not be a perfect agreement but it is without doubt a huge step in the right direction. Having no agreement – and therefore allowing Iran to continue with its nuclear programme with absolutely no control over it – would certainly have been a much worse outcome.

The deal has sharply decreased the chance of a war and has the potential to open up a new chapter in relations between Iran and the West (in particular the United States) and to change the geo-political dynamics of the region. It also offers Iran the possibility of playing a constructive role in the Middle East and sends out the message that diplomacy, compromise and negotiations are indeed possible between countries that have been adversaries for quite some time.

Credit is due to all those who made this deal possible, in particular US President Barack Obama and Iran’s President Hassan Rouhani, both of whom faced fierce opposition at home from hardliners. Obama showed the international community that diplomacy can work and that war is not always inevitable.

In a nutshell, here are the main points of the landmark deal which will curb Iran’s nuclear programme in exchange for sanctions relief:

Enrichment: Iran will reduce its number of uranium-enriching centrifuges from 20,000 to 6,104, and reduce the number of those in use from 10,000 to about half. Those limits will be in place for 10 years, and then gradually relaxed over the next three. Enriched uranium is a critical component for both civil nuclear power generation and military nuclear weapons.

Stockpiled uranium: Iran has already got rid of stockpiled uranium that was enriched to one step from weapons-grade material. It has now agreed to reduce its remaining stockpile of less-enriched uranium that is harder to use for nuclear arms, from about five tons to 300 kilograms for 15 years. At this level it would take Iran at least a year to enrich enough uranium for a nuclear weapon.

Underground site: Iran has promised to convert its Fordo enrichment site dug deep into a mountainside into a research centre. The site will still house centrifuges but they will make medical isotopes instead of enriching uranium.

Inspections: Iran will give more access to its nuclear programme to the International Atomic Energy Agency. If UN inspectors identify a suspicious site, an arbitration panel with a Western majority will decide whether Iran has to give the agency access within 24 days. All sites, including military ones, may be inspected if the agency has solid evidence of undeclared nuclear activity.

This deal should be welcomed by everybody because it has reduced the possibility of war and has the potential to change the region for the better

Reactors and reprocessing: Iran must redesign its nearly built reactor at Arak so it can’t produce plutonium for nuclear weapons.

Sanctions relief: All US, UN and EU nuclear-related sanctions will be suspended after experts verify that Iran is sticking to its commitments. If at any time Iran goes back on its word the sanctions will snap back into place. An arms embargo will remain in place for five years and restrictions on Iran’s ballistic missile programmes for eight.

Of course, as I said earlier, this is not a perfect deal. For example, the accord does not eliminate Iran’s ability to build a nuclear bomb but lengthens the time it would take if Tehran decided to pursue such an option. Furthermore, we can never be sure that UN inspectors will be able to detect a secret nuclear programme, but the risks for Iran if it had to operate such a programme are huge.

One also needs to look at the political implications of this deal, in particular the possibility of improved relations between Washington and Teheran, which could have far-reaching implications for the entire Middle East. I believe both countries need to come to terms with their past relationship, apologise for any mistakes (such as the CIA overthrow of Iranian Prime Minister Mohammad Mosaddegh in 1953 and the taking of US embassy hostages in the 1979 Islamic Revolution) and start afresh.

Constructive engagement between the US and Iran – which has a lot of influence in the Shi’ite Muslim world – can be a force for stability in the world, but we shouldn’t expect a sudden massive improvement in ties between the two countries. However, attempts should now be made for the two countries to establish diplomatic relations.

Now that sanctions on Iran are being removed, the regime will acquire billions of dollars in unfrozen assets which will no doubt boost the economy. Hopefully this will increase support for the moderate President Rouhani who may be encouraged to pursue a pragmatic foreign policy and to introduce political and economic reforms. Having said that, however, this will be a slow process and Rouhani always has to work in the shadow of Iran’s hardline Supreme Leader, Ayatollah Ali Khamenei, who has the final say in foreign and security policy.

Nevertheless, an Iran fully engaged with the international community can play a constructive role, if it so chooses, in Iraq, Syria, Lebanon, Yemen and in the war against Islamic State. At the same time the US and the EU must be careful to balance their engagement with Iran with their continual friendship with their traditional Sunni Muslim allies, especially in the Gulf. But the message Washington and Brussels need to send out is that Shi’ite Iran and Sunni Saudi Arabia (where different sections of society have unfortunately criticised the deal) must enter into a new phase of constructive engagement and work together towards peace and stability in the Middle East.

This nuclear accord has sadly been condemned by Israel, with Prime Minister Benjamin Netanyahu dismissing the deal as a “historic mistake”. In the US, the Republicans in Congress and most candidates for the Republican presidential nomination have also criticised the deal. Yet both Israel and the Republicans have offered no credible alternative to the negotiated settlement.

The US Congress, controlled by the Republicans, now has 60 days to review the agreement during which time President Obama cannot lift the Iran sanctions . Congress can reject the deal and keep the sanctions in place, but Obama has vowed to veto such a rejection. Congress would need a two-thirds majority to overturn the veto.

This deal should be welcomed by everybody because it has reduced the possibility of war and has the potential to change the region for the better.