The negotiations over Iran's nuclear energy program and the possibility of reaching a concrete agreement to insure that Iran does not someday decide to build a nuclear weapon was doomed from the start because it was based on a completely false pretense. Iran is not building a nuclear weapon. It has not even made a decision to seek such technology, and the CIA and Mossad have both made public statements confirming this. The talks pretended to address an accusation that the United States and its allies know full well is a lie, and if the negotiations had resulted in an actual agreement NATO powers would have lost their main line of rationalization for their incessant saber rattling with Iran. They weren't about to let that happen, but they had to maintain appearances. After all the U.S. couldn't be seen as rejecting a reasonable deal that actually made their military options impossible to whitewash.
So the deal had to be scuttled, but in such a way that didn't draw too much attention to the culprits. As is becoming a pattern in this game France played a key support role by taking a hardline approach and reportedly rejecting a proposal that the other Western powers had placed on the table. This while the U.S. congress muddied the waters even more by proposing new, tougher sanctions on Iran while the negotiations were still in progress. The Obama administration made public statements condemning the move by congress saying that it would lead to war with Iran, but this was just an example of the good cop bad cop technique. The damage was done while still allowing the White House to come off as reasonable. Make no mistake though, those who control Obama want war with Iran. They don't want a political solution.