The successful outcome of the negotiations over Iran’s nuclear program provides a splendid validation for those who put their faith in diplomacy. The agreement – concluded after more than a decade of talks – highlights the value of persistence in addressing impasses that seem insurmountable, and provides hope for the many other initiatives that will be needed to bring lasting peace to the Middle East.

The European Union, which initiated the talks, should be proud of its effort. And the United States’ role was remarkable, from Secretary of State John Kerry’s incessant work, even on crutches, to end the 35-year standoff between his country and Iran, to President Barack Obama’s critical push to complete the negotiations. Likewise, Iranian President Hassan Rouhani should be commended for his determination to complete the undertaking he began more than a decade ago, when he served as secretary of Iran’s Supreme National Security Council.

Rouhani and I met in 2003, sitting across from each other at the first nuclear talks, when our negotiating team was made up of only Europeans. Mahmoud Ahmadinejad’s election as President of Iranin 2005 derailed those talks and ultimately led to the imposition of sanctions. But I had seen how determined Rouhani was to reach an agreement. And, indeed, when Rouhani succeeded Ahmadinejad in 2013, a door opened.

Rouhani invited me to his inauguration in August 2013. During that visit, I was able to attend meetings with him and other top Iranian leaders, including Mohammad Javad Zarif, Iran’s foreign minister and, later, its chief negotiator in the negotiations in Vienna. I quickly saw that with these men at Iran’s helm an agreement would be possible.

The agreement – known as the Joint Comprehensive Plan of Action – limits Iran’s nuclear program to peaceful purposes in exchange for lifting all international sanctions on the country. For the next 15 years, Iran will not be permitted to enrich uranium to more than 3.67 percent (to build a nuclear bomb requires uranium enriched to at least 85 percent). Enrichment will be permitted only at the nuclear facility at Natanz – not at the subterranean Fordow installation. And Iran will have to keep its stock of 3.67 percent-enriched uranium to below 300 kilograms.

Moreover, the JCPOA will oblige Iran to reduce its number of centrifuges, which are used in the enrichment process, progressively for the next 10 years. Likewise, the heavy-water reactor at Arak will have to be redesigned to produce only radioisotopes for medicinal and industrial purposes, or for research into other peaceful uses of nuclear energy, with the spent fuel it produces shipped out of the country.

Most important, Iran has committed itself to applying the Additional Protocol of the International Atomic Energy Agency, providing the organization with round-the-clock access to all components of its nuclear program for 15 years. The IAEA will also monitor the production of centrifuges for 20 years.

The agreement was made possible by the fact that Iran’s interlocutors – the five permanent members of the U.N. Security Council plus Germany – were able to maintain a common position during a process that played out for more than a decade. This was true even during the negotiating push, when a debate over the sanctions against Iran’s trade in conventional arms and ballistic missiles threatened to open a breach between the partners. WhileRussia and China asserted that signing an agreement would render any kind of sanction legally unjustifiable, the United States sought to allay the fears of Iran’s neighbors as much as possible.

The consensus among the negotiating partners – one of the few points of agreement regarding the Middle East among the Security Council’s permanent membership – was crucial in convincing Iran to take the negotiations seriously. And, at a time of persistent tension between Russia and the U.S. and Europe, which has resulted in chronic political gridlock in the Security Council, the parties’ ability to remain united justifies greater optimism about the future.

Indeed, it is worth considering whether cooperation between the permanent members of the Security Council and the European Union might be useful for moving forward on other matters. The West and Russia share an interest in stability in the Middle East, as does China, which is particularly concerned with the security of its energy supplies.

What is most needed – and most difficult to achieve – is a rapprochement between Iran and Saudi Arabia. Many of the conflicts in the Middle East have their roots in the tension between Sunni and Shiite Islam. Cooperation between Sunnis and Shiites will be vital to defeat the extremism of ISIS, as well as to bridge gaps between combatants in Syria, Iraq, Yemen and Lebanon. Iran must demonstrate that it is a responsible player in the region – not simply a backer of Shiite power.

The re-establishment of ties between the United States and Iran will, no doubt, have repercussions in Israel and Palestine. Although the agreement with Iran objectively makes Israel safer, Prime Minister Benjamin Netanyahu considers it a historic error. To assuage its traditional ally’s sense of abandonment, the U.S., may – mistakenly – withhold support for the initiatives recognizing the State of Palestine in the coming months. But it is essential that the EU, which finances and maintains Palestine’s provisional institutions, not relent in its determination to make them permanent.

The historic agreement with Iran is just one of many that will be required to bring peace and stability to the Middle East. The first hurdle has been overcome. We must now run the rest of the race.