The final hours before Iran and the six world powers agreed on a framework about Iran's nuclear program were crucial; Iranian Foreign Minister Mohammed Javad Zarif and his negotiating team considered leaving the talks and returning to Tehran. Their plane was ready, and Zarif and his team, even some of the major powers who were participating in the talks, were not disappointed with what was achieved by that point. It was US Secretary of State John Kerry who decided not to give up, and the final attempt at a deal lasted from 9 p.m. on April 1 until 6 the following morning. Kerry and Zarif believed it was the last chance to reach a deal — one that no one had been able to reach before. Both sides stuck to their own tough talking points, but it was clear that the lines were drawn far away from the edge of the abyss.

“We arrived at a common understanding on many of the main points,” a senior Iranian official told Al-Monitor on condition of anonymity. “What’s left are the very complicated details that need thorough discussion; despite all the sessions and the mutual confidence that was built, each party remains cautious toward the other. Iran wasn’t ready to sacrifice at any cost, the least for promises that might be respected or might not. How is Iran going to implement the agreement without people immediately feeling the change?”

Lifting the sanctions was the main issue. Everyone knew that lifting the sanctions gradually would not be acceptable to the Iranians — the main line drawn by the supreme leader, Ayatollah Ali Khamenei. Everything was ready for an agreement except for this point, in addition to a few other issues. According to information acquired by Al-Monitor from multiple sources in Tehran, a compromise was made that appeased both sides, with Iran and the United States being able to present it in a way that serves their own interests.

One official source in Tehran said, “The trick was the implementation of the agreement and its timing. The world powers want to see implementation [of the agreement] before sanctions are lifted, while Iran wants both simultaneously. The solution was a framework deal that allows Iran to prove its goodwill and the other side would lift the sanctions after the agreement was signed and things get on the right track.”