Per the Wikipedia entry on nuclear programs:
Red: Five "nuclear weapons states" from the NPT.
Dark orange: Other known nuclear powers.
Yellow: States suspected of having possession of, or suspected of being in the process of developing, nuclear weapons and/or nuclear programs.
Purple: States which at one point had nuclear weapons and/or nuclear weapons research programs.
Green: Other states capable of developing nuclear weapons within several years if the decision to do so were made.
The cited article is a Bret Stephens column in the WSJ lambasting Obama over the Turkey-Brazil-Iran deal, which presents all the same face-saving potential as the old Russian deal we pushed a while back (and Iran rejected). In short, it buys us maybe 10 months of stockpile setback from the Iranians.
But Stephens point is a larger and more valid one: the south-south diplomacy here outmaneuvers the braindead American approach on sanctions. The Iranians don't even have to resort to chess: they're killing us at our own game of checkers.
My point--as usual: check out the map, and note how membership in the Core tends to correlate with nuclear capacity, with all the newbies lying not far off the Seam. People are knocking at the door. You can let them in or keep them out, but their pursuit of nukes is a backdoor route toward recognition of great-power status that will not be wished away with sanctions. In the end, nukes are the symptom, not the driver. The only solution that matters is effective integration into the Core, whereupon their ownership of nukes no longer matters. So long as we keep nukes at the center of our foreign policy, the more hamstrung we become in the processing of their "applications"--as it were.