THE PAYOFF:

Iran's population, the majority of them young, yearn, like all of us, for the opportunity to build their own lives and careers, to study, travel and work freely.

A country as great as Iran, a country with so much history, ambition and potential, should never have been so restricted. Sanctions have taken a brutal toll on ordinary Iranians. On this side of the Arabian Gulf, we have never wished that pain on the Iranian people - but we have also wished for responsible behaviour from the Iranian government. Stopping Tehran from acquiring nuclear weapons would indeed be, as Saudi Arabia said yesterday, "a happy day".

This, then, is an historic moment for Iran and for Iran's leaders. They face a crucial choice and an important test. On Twitter, Iran's president Hassan Rouhani wrote: "With this unnecessary crisis resolved, new horizons emerge with a focus on shared challenges." If Mr Rouhani and his government genuinely mean that sentiment, and demonstrate it in the coming months, a new era in Arab-Iranian relations will have opened.

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