The failure of Iran and the P5+1 (the five permanent members of the UN Security Council plus Germany, also known as EU3+3) to reach a comprehensive nuclear agreement by their self-imposed 24 November deadline was no surprise. The process had been deadlocked for months over two key issues: the size of Iran’s enrichment program and sanctions relief. For want of a last-minute breakthrough, the parties agreed to a new seven-month extension, with the goal of reaching a political agreement by 1 March 2015 and a comprehensive agreement, including an implementation plan, by 1 July 2015. A landmark agreement can still be found if both sides adopt more flexible postures. As Crisis Group has previously written and here reiterates, they can do so without violating their core principles and interests.

Though many sceptics took the extension as confirmation that the entire process is doomed, the parties made considerable progress in Vienna and narrowed their differences on a multitude of issues over the past twelve months. Talks were slowed by the cumbersome multilateral framework and an ill-advised decision to jointly tackle political and technical questions, but as the deadline loomed, negotiators tweaked the process, increased the pace and seriousness of the talks, and affirmed a heightened spirit of dialogue and trust. While an agreement proved elusive, both sides expressed their core political requirements more clearly than before. As a result, never have negotiators had a better understanding of their counterparts’ positions and constraints.

While ultimate success is far from guaranteed, negotiations, in a little more than twelve months, have achieved more than years of escalation: the P5+1 has managed nearly to double both the tempo of inspections and Tehran’s nominal breakout time, the interval required to enrich enough fissile material for one weapon; Iran has pared back sanctions and started to restore its image by honouring its commitments under the November 2013 interim accord. Yet differences remain sharp and overcoming them will grow more difficult with time, as the voices of sceptics get louder. Iran’s redlines are two-fold: first, recognition of its right to industrial-scale enrichment and, secondly, that any irreversible concessions it makes will be met with commensurate steps on sanctions – specifically their termination, not just suspension. As for the P5+1, it insists on denying Iran a breakout time of any less than a year, as well as on maintaining the sanctions architecture – even if some are suspended – for the duration of the comprehensive agreement, since they are the group’s most effective leverage.

As difficult as forging an agreement will be, there is considerable value in having clarified what stands in the way. It would be as grave a mistake to underestimate how far the negotiators have come as it would be to overestimate their chances of success. Obstacles notwithstanding, there is a credible path to an agreement. It would require for Iran to postpone its plans for industrial-scale enrichment while the P5+1 countenances controlled growth of that program and clearly defines target dates for a phased lifting of sanctions.

Now that the fog has receded, the parties should move ahead quickly. The positive momentum will soon fade, and with it, the chances for a peaceful resolution of this protracted crisis.

Istanbul/Vienna/Brussels, 10 December 2014