Iran: the fear of failure

Under the facade of smiles, flush with the tension in Lausanne.

Negotiators have more than a few hours - until midnight Tuesday - to reach an agreement on the Iranian nuclear program.

Twelve years after the start of talks, the progress but there are still several sticking points, including the duration of the guardianship of Iran's nuclear, the timing of the lifting of sanctions and the possibility to re-impose for breaches of Tehran.

"The fact of reaching agreement is undoubtedly a success of a diplomatic point of view - solve all the complicated problems, some of which are in negotiations for 12 years and others for 18 months, is a great progress, but it is not synonymous with ultimate success, "said Ali Vaez, Iran expert at the International Crisis Group.

"The possible agreement is still vulnerable and in the months to come, there will be pressure from outside comers. To write it agreed text and whatever it takes to add a technical or political point of view, it will be very complicated, "he adds.

Anyway, the US Secretary of State John Kerry and the head of the Iranian Foreign Mohammad Javad Zarif can not return to their countries with empty hands, for lack of opponents to consolidate this agreement.

It will take them, at least, to agree on some key points to negotiate an extension to their parliaments discussions on failure.