WASHINGTON -- President Barack Obama's hopes for a nuclear deal with Iran now depend in part on his ability to keep a lid on both hard-liners on Capitol Hill and anxious allies abroad, including Israel, the Arab Gulf states and even France.
Each of the wary parties is guided in some measure by domestic political interests. But they also share concerns that Obama may want a breakthrough with Iran so badly that he would be willing to accept a deal that prematurely eases economic pressure on Iran and gives the Islamic republic space to pursue a nuclear weapon.
"All of us want to see diplomacy," Sen. Bob Corker, R-Tenn., told NBC News. "But we're also concerned about an administration that seems really ready to jump into the arms of folks and potentially deal away some of the leverage we have."
Indeed, there's little question Obama desires a deal with Iran, which could give him a boost during a shaky stretch in his presidency that has included the deeply flawed rollout of his signature health care law, new revelations about U.S. government spying and falling approval ratings. Successful negotiations with Iran also could validate Obama's long-held belief that the U.S. should be willing to talk to adversaries without preconditions.
Obama and his advisers reject the notion that they are naive about Iran's intentions. And they insist the world must test whether new Iranian President Hassan Rouhani is serious about his announced desire for improved relations with the West.
Colin Kahl, who served as a top Pentagon Middle East official during Obama's first term, said the very fact that the success or failure of a nuclear agreement would be so critical to Obama's presidency ensures the administration won't sign off on a subpar agreement with Tehran.
"The president sees preventing Iran from getting a nuclear weapon as not only central to vital U.S. national security interests, but also to his own legacy," said Kahl, now a senior fellow at the Center for a New American Security. "They're not going to accept a bad deal."
Talks between Iran and six world powers -- the U.S., France, Russia, China, the United Kingdom and Germany -- ended over the weekend without an agreement on a preliminary deal that would have set the stage for broader talks. Diplomats said talks broke down in part because the international powers refused to formally recognize Iran's right to enrich uranium.
France also expressed concerns that proposed limits on Iran's ability to make nuclear fuel don't go far enough. France also sounded alarms over a planned heavy water reactor that would produce greater amounts of byproduct plutonium, which can be used in nuclear weapons production. Western officials later tried to gloss over the French concerns, but their public comments raised questions about cracks in the international coalition.
Iran insists it is not pursuing a bomb and only wants to enrich uranium for energy and medical applications.
Negotiations are due to resume in Geneva on Nov. 20. In exchange for nuclear concessions from Iran, the U.S. and world powers are offering Tehran limited and reversible relief from economic sanctions that have strained its economy.
In the days leading up to the next round of Geneva talks, Obama is likely to confront renewed skepticism from congressional lawmakers and allies overseas.
Some U.S. lawmakers oppose the president's willingness to ease sanctions on Iran, even temporarily, and instead want to layer on new economic penalties. At the Obama administration's request, a sanctions bill in the Senate Banking Committee was put on hold, but it's unclear how much longer lawmakers are willing to wait.
Obama personally placed a call last week to Sen. Mark Kirk, R-Ill., a key sanctions drafter, to ask that legislation be stopped. Vice President Joe Biden, Secretary of State John Kerry and White House chief of staff Denis McDonough have all talked with lawmakers in recent days. And the White House is dispatching Kerry to Capitol Hill on Wednesday to implore the Senate Banking Committee to pause the legislation once again.
The U.S. also is being squeezed abroad by allies, most notably Israel, which sees Iran's pursuit of a nuclear weapon as an existential threat. Israeli Prime Minister Benjamin Netanyahu characterized the outlines of an agreement that had appeared to be emerging last week as "the deal of the century" for Iran.
His comment prompted a call from Obama to reassure the Israeli leader that the U.S. still agrees about the need to prevent Iran from obtaining a nuclear weapon. Wendy Sherman, the top U.S. nuclear negotiator, also traveled to Jerusalem following the Geneva talks to try to assuage Netanyahu's fears. And there are certain to be more high-level discussions between the U.S. and Israel over the next 10 days.
The Obama administration also is trying to ease concerns among allies in the Gulf, including Saudi Arabia and the United Arab Emirates, which have expressed wariness about interim agreements that would allow Iran to keep enriching uranium. Kerry visited Saudi Arabia last week and stopped in Abu Dhabi on Monday.
After decades of frozen relations, Obama has rapidly ratcheted up diplomacy with Iran in recent months, making little secret of his desire to test the waters for nuclear negotiations.
Obama reached out to Rouhani through a series of letters this summer, sparking speculation that the two might meet face-to-face while they both attended meetings at the United Nations in September. When that meeting failed to transpire, the White House made clear that it was Rouhani, not Obama, who balked at the last minute.
Days later, Obama and Rouhani spoke by phone, a historic call that marked the first direct conversation between a U.S. and Iranian leader in more than 30 years. There have since been several lower-level meetings between American and Iranian officials.
Polling shows Americans back Obama's call for direct negotiations with Iran. A CNN/ORC International poll conducted in late September found 76 percent of Americans favored direct diplomatic negotiations with Iran aimed at preventing the Islamic republic from developing a nuclear weapon. Twenty-one percent opposed direct negotiations.