Gholamreza Aghazadeh, one of Iran's vice presidents who has headed Iran's nuclear program for the last several years, tendered his resignation three weeks ago. That resignation has just been accepted by President Mahmoud Ahmadinejad.
The reason most news sources give for the resignation is Aghazadeh's association with Mir Hossein Mousavi. That seems reasonably likely, but let me go 'way out on a limb here.
Ever since the uprising over Iran's elections began, I have been concerned about the politics of Iran's nuclear program. It has seemed likely to me that what Robert Oppenheimer called a "sweet problem," the making of a rapid chain reaction, has appealed just as much to some Iranian scientists and engineers as it has to others.
As India, Pakistan, and Israel were developing their nuclear programs, such factions existed. When political turmoil hit their countries, these scientists and engineers used that turmoil to make progress on weapons-related technology and to extend their political power.
Trita Parsi recently confirmed to me that such a faction exists in Iran. I can hardly believe that they are not making their case to the politicians and mullahs. The technical progress is inhibited by the presence of IAEA inspectors.
Aghazadeh's resignation opens the way for politicking by this faction. Whether they get one of their people into this position remains to be seen. Even when someone is appointed, it will not be clear because we know so little of Iran's internal politics.