In March 2009, U.S. President Barack Obama directly engaged the Iranian people during the celebrations of Nowruz, the Persian New Year writes Guillaume Xavier-Bender. He used the words of the Persian poet Saadi: “The children of Adam are limbs to each other, having been created of one essence.” The tradition on the last Wednesday before Nowruz is to jump over fire, and it seemed at the time that the president was doing exactly that in his outreach to Iran.

Six years later, the fire may still be burning, but the wind is at last blowing in a more favorable direction. On April 2, Iranian State Television broadcast Obama’s live remarks from the White House’s Rose Garden as he responded to the deal struck by nuclear negotiators in Lausanne. It had taken two extra days and nights of talks to reach an agreement on the key parameters of a Joint Comprehensive Plan of Action between Iran and representatives from the United States, France, Britain, Germany, Russia, China, and the European Union, but this shift may have longstanding regional and global consequences.

At least five lessons can be derived from the tentative agreement. First, diplomacy works. U.S., Iranian, and other negotiators worked long hours, made concessions, and reached a mutually acceptable deal. Second, diplomacy works best when the United States acts together with its allies and partners. Third, the negotiations showed that artificial deadlines are useful but are also meant to be broken. Rigidity and haste add no value to solving complex equations. Fourth, leaders and negotiators on all sides do not lack resolve and ambition.

The greatest challenges to reaching a final agreement in June will lie more in domestic politics and external events. Fifth, Iran is back. This has implications that reach far beyond the content of any final nuclear deal. As such, it is crucial to look at the negotiations with Iran from some distance, and to not lose sight of the forest for the trees. While any acceptable final deal with Iran will advance nuclear non-proliferation, the meaning of the talks themselves far exceeds the content of any agreement.

In this new context, what could a re-engaged Iran mean for the balance of power in the Middle East? What could it mean for U.S. relationships with Israel and Saudi Arabia in particular? What could Russia and China gain from a successful deal? What could it mean for the European Union and its burgeoning foreign policy? And would a nuclear deal lead to a normalization of relations between Washington and Tehran?

Before his address from the Rose Garden, Obama spoke to King Salman of Saudi Arabia to reaffirm the U.S. commitment to the security of its partners in the Gulf. The president also called for a meeting with countries of the Gulf Cooperation Council in Camp David this spring. Four days later, Saudi Arabia cautiously endorsed the framework agreement, encouraging good neighborliness from Iran. This statement contrasted vividly with Israel’s reaction and Prime Minister Benjamin Netanyahu’s concerns that the deal would give Iran a free path to the bomb, and will spark an arms race in the Middle East. These different views reflect different perceptions, different interests, and different constituencies. But all will have to be taken into account as the United States and its partners make their next moves.

Without any doubts, much remains to be done to broker a final deal by June 30. But the momentum and leadership to do so is there at the highest level. Even Iran’s supreme leader, Ayatollah Ali Khamenei, seems to be giving the talks a chance. However difficult and frustrating reaching an agreement might prove to be, the U.S.-Iran relationship will play a determining role in the future of regional and global politics. In the medium term, the possibility of a new entente cordiale is real.

There are four remaining verses to the Saadi poem that Obama quoted from back in 2009: “When the calamity of time afflicts one limb, the other limbs cannot remain at rest. If you have no sympathy for the troubles of others, you are not worthy to be called by the name of ‘man’.” Perhaps the president is waiting for a final deal to finish reciting them. They were written by Saadi in what in Farsi is called the Golestân. In English, it is The Rose Garden.

Guillaume Xavier-Bender is a transatlantic fellow in the Brussels office of The German Marshall Fund (GMF). This article was first published by the GMF.