With such a lengthy timetable, IAEA inspectors roaming Iran, and American troops in Afghanistan and Iraq, Tehran may have chosen to outsource plutonium production to Syria - a safer option, because al-Kibar was still undetected, and a faster one, because by then North Korea was technologically ahead of the game.
That's the biggest problem with treating the symptoms (nuclear advancement) rather than the disease (the regime itself). I don't worry about France with nuclear weapons. I worry about Iran under the mullahs without nuclear weapons.
If Iran's people go out on the streets again to protest their regime, I hope we don't give them the back of our outstretched hand (again).