Some small fractures are showing up in the wall of solidarity the U.S. and its partners have tried to show in confronting Iran over its nuclear program -- specifically over how long to give diplomacy a chance before turning to new economic sanctions.
But the more meaningful stress fractures are showing up within Iran itself. There, the unwillingness to follow through on a nuclear deal the country's own negotiators worked out -- or even to offer a straight explanation of why Iran isn't following through -- has laid bare serious fissures within the country's ruling establishment.
If that continues to be the case, the U.S. and its partners will be heading in coming weeks toward a fundamental question: Are these splits within Iran more likely to be widened by the pressures generated through continued diplomacy, or by the pressures generated by tough new economic sanctions?
That's the picture that emerges from conversations in recent days with both American and European officials familiar with the diplomatic engagement with Iran. None pretend to have perfect knowledge of what is happening within the Byzantine world of Iranian decision-making, which has been made all the more complicated by the divisions opened up amid protests over what is widely seen as a rigged presidential election there during the summer.
The subject on which Iran is incapable of rendering a coherent decision is the deal that was struck -- or seemingly struck -- at that meeting in Geneva. Under that agreement, Iran would ship to Russia and France a large proportion of the low-enriched uranium it has managed to produce, so that the uranium could be refined into fuel for a Tehran research reactor and sent back to Iran.
The beauty of the deal for the U.S. and its negotiating partners -- the other members of the United Nations Security Council plus Germany -- was that it would take a majority of the Iranian raw material that eventually could be further enriched into nuclear-bomb fuel and allow the international community to turn it into something else, under close supervision.
But since Iran's own negotiators seemed to agree to that arrangement, their leaders back in Tehran have pedaled backward, and then sideways, and then in circles, never embracing the deal but never exactly rejecting it either.