As I see it, everyone involved has a piece or pieces of the truth in this highly complex situation. The problem is to try to put all the pieces together so they make some kind of coherent picture.
Of course there are divergent strands of thought within the elite of the Islamic Republic. There always have been and they are often acted out in public, though not always. Zarif and Rouhani represent one strand that walks a tightrope between not annoying Khamenei and trying to protect Iran’s interests with reference to the outside world.
We also know that Iran is for all practical purposes a nuclear power, although public admittance of that fact may be long delayed (cf. Israel). We also know that the current administration in Washington is totally incapable of any kind of strategic thinking, planning or action. It is all slogans: “reset”, “pivot”, etc.). Consequently, the obvious Western strategy, which the French intermittently champion, comes down to maintaining and strengthening sanctions until such time as Iranian behavior turns decisively for the better or regime change takes place will not happen. The sanctions regime is already crumbling on the assumption that something or other will be signed on June 30th.
Which leaves only one alternative, which frankly, though far from perfect or even good, is not without merit. Wait. Sign whatever you want, the Iranians will violate it anyway. After regime change in Washington, D.C. on January 20, 2017, actively encourage dissidents within the Iranian hierarchy and outside the government to see what can be done. By that time the Mullahs will hopefully understand the Pandora’s box they have broken open and that they will soon be surrounded by nuclear-capable Sunni powers.
The trick is to get through to January 2017 in one piece and that the subsequent administration be at least modestly rational and competent..