France’s hard line on enrichment did, however, cast it as the outlier in Geneva. Matters were not helped by French Foreign Minister Laurent Fabius, who reportedly irritated P5+1 colleagues by rushing out to announce the failure to reach a deal even while an official communique was being painstakingly hammered out. Earlier, Fabius had warned that Paris would reject anything it suspected of being “a con game” by Iran, clashing with the optimism from diplomats in Geneva about prospects for agreement

The Iranians took the opportunity to blame the failure to conclude a deal on what Iran’s Foreign Minister Mohammad Javad Zarif called “differences of opinion within the P5+1 group.”

Casting France as the deal wrecker may be an exaggeration, but Paris is clearly less inclined than its Western allies have been to accept Iran’s continuing uranium enrichment, even under the stricter caps and tighter scrutiny at the heart of compromise formulas that have formed the basis for the recent progress.

France suspects that Iran’s nuclear work is directed toward military goals and believes that a nuclear-armed Iran should be prevented at any cost. Whereas President Barack Obama has declared a willingness to take military action if necessary to prevent Iran’s acquiring nuclear weapons, the U.S. believes Iran has not yet decided to build the bomb even though it has built much of the technological infrastructure enabling it to do so.

Since Iran in 2005 ended the voluntary freeze on enrichment that it agreed to the previous year with the European Union, Paris has been wary of Iranian concessions and promises of good behavior. That mutual enmity was underscored by former French President Nicolas Sarkozy and former Iranian President Mahmoud Ahmadinejad’s trading personal insults in public. While Sarkozy’s socialist successor, François Hollande, has adopted a more diplomatic style, he hasn’t softened the French stand on Iran.

Hollande reportedly shares concerns among French strategists that Obama may be so eager to encourage a more cooperative position from Tehran that he would accept a flawed nuclear agreement. France is also skeptical of the Geneva draft’s provision of a six-month suspension of Iran’s nuclear work in order to reach a permanent agreement — a period Paris fears could be used by Tehran to take its nuclear work underground and even create a bomb by mid-2014. That’s why France insists Iran’s current stockpile of 20 percent enriched uranium, which can be rapidly transformed into weapons-grade materiel, be eliminated or stored outside the country rather than rendered into a form more difficult to process into bomb materiel (as has been proposed in the current talks). France has also been tougher than its partners regarding Iran’s Arak heavy-water reactor, which, once operational, will produce plutonium that could be used for nuclear warheads. Paris wants a total halt in construction of Arak during the six-month freeze rather than simply limited progress, as negotiators had been considering.

Still, despite France’s harder line, its diplomats confide that Paris won’t torpedo a deal if Iran is ready to accept it, if it's enforceable and if it would prevent Tehran from developing nuclear arms.

Some observers see other strategic objectives in France’s taking a harder line than its Western allies on Iran. Its position syncs with Saudi Arabia’s — a common cause that could increase Paris’ posture as a major ally and business partner as the kingdom’s traditional partnership with an inward-turning U.S. starts to falter. The U.S. desire to reduce its international footprint may also be prompting French and other European leaders to seek a greater leadership role in international affairs. That much was clear in France’s leading role in interventions in Libya and Mali.

France no longer assumes that following the U.S. lead necessarily produces desired results. Hollande had, just two months earlier, led efforts to rally international backing for Obama’s call for military strikes on Syria, only to be left dangling after the White House unilaterally reversed its course. Now that the focus has shifted to seeking a solid nuclear agreement with Iran, the French appear to have calculated that it’s more prudent to seek a leading role at the negotiating table.

Bruce Crumley is a freelance journalist based in Paris, where he spent two decades working as a correspondent for TIME magazine.