DUBAI, United Arab Emirates – Iran wants U.S.-led sanctions rolled back, and Western nations and others seek to limit Iran's ability to enrich uranium to levels that could lead it closer to producing nuclear weapons. But negotiators face resistance from Western allies such as Israel and Gulf states toward any pact that keeps Iran's nuclear program generally intact and dissent within Iran from hard-liners opposing any nuclear concessions or diplomatic outreach to Washington.
It's unlikely that critics could derail international efforts to ease one of the Middle East's most far-reaching standoffs, which has brought Israeli threats of military action, past warnings by Iran it could block critical oil tanker shipping lanes in retaliation for sanctions and opened rare public discord between the U.S. and Saudi Arabia.
But the voices of opposition could influence the speed and scope of nuclear talks. It also has the potential to further reshape relations between the U.S. and two of its main allies in the region, and bring deeper tensions and brinksmanship within Iran between hard-line forces and the moderate-leaning government of President Hassan Rouhani.
Israeli Prime Minister Benjamin Netanyahu said Friday that he "utterly rejects" any emerging nuclear deal between Western powers and Iran, and pledged that Israel would do what was needed to defend itself — a clear reference to past warnings of military action to degrade Iran's nuclear capabilities.
Israeli leaders believe Iran not has wavered from its aim to develop a nuclear weapon despite the Islamic Republic's repeated insistence that it seeks reactors only for energy and medical applications.
Israel considers a nuclear-armed Iran to be an existential threat, citing hostile Iranian rhetoric toward the Jewish state, Iranian missiles that can reach Israel and Tehran's support for anti-Israel militant groups led by Lebanon's Hezbollah.
Netanyahu says pressure must be maintained until Iran halts all enrichment of uranium, rids itself of its stockpile of enriched uranium and closes enrichment facilities. Israel also wants Iran to halt work on a heavy water reactor, which produces a greater supply of plutonium byproducts than Iran's sole conventional reactor. Plutonium can be processed for use in a nuclear weapon, although Iran is not believed to currently possess the technology.
Israel also is worried about any shift in the region's strategic balance. Israel is widely believed to have the only nuclear arsenal in the Middle East, although Israeli officials neither confirm nor deny the speculation.
For years, Saudi Arabia's King Abdullah repeatedly urged the United States to "cut off the head of the snake" by attacking Iran's nuclear facilities. Now, Saudi officials are dismayed over Washington's efforts to end the 34-year diplomatic estrangement with Tehran.
Saudi Arabia and the other Gulf states consider Iran as their chief rival in the region and — in a rare alignment of views — side closely with Israel's outlook that Iran should be stripped of its ability to enrich uranium. Gulf states are major buyers of advanced U.S. military equipment, but Saudi Arabia has hinted it could one day build closer strategic ties with nuclear-armed Pakistan as a way to guarantee its own de facto nuclear weapon status to counterbalance Iran. Washington, which has often said it fears an atomic arms race in the Gulf, would certainly oppose such an alliance.
But Saudi relations with the U.S. have reached a difficult juncture. Saudi officials have openly criticized President Barack Obama for his outreach to the new Iranian president. Last month, Saudi Arabia rejected a seat on the U.N. Security Council to reinforce its protest the U.S.-Iranian diplomatic exchanges and the U.S. decision to pull back from possible military strikes against Syrian President Bashar Assad's forces and instead back a Russian-drafted plan to collect and destroy Assad's chemical weapons supply. Saudi Arabia and other Gulf states are key backers of rebels seeking to topple Assad.
Late last month, banners began appearing around Tehran that depicted the U.S. as a manipulative and bullying negotiating partner seeking to undermine Iran any way it can. No group claimed ownership of the messages, but that was unnecessary in a country where it's already clear the forces that are lining up against any deals that could somehow close the diplomatic chasm with Washington.
Hard-liners led by the powerful Revolutionary Guard and its vast network of backers have strongly opposed the stirrings of rapprochement started by Rouhani. Last Monday, they organized the largest anti-American demonstration in years to mark the anniversary of the 1979 takeover the U.S. Embassy after the Islamic Revolution.
The dissent, though, has its limits.
Rouhani's critics are not likely to stand in the way of a possible nuclear deal with the West since the negotiations have the support of Iran's Supreme Leader Ayatollah Ali Khamenei. Also, the public largely supports bids to ease sanctions and even hard-liners do not want to be on the wrong side of that issue.
Hard-line pressure can gain ground, however, on how far Khamenei would allow diplomatic overtures outside the nuclear talks. Rouhani appears willing to extend the dialogue to other areas — possibly even Iran's support of Assad — but any moves must be cleared by Khamenei, who may not want to further anger the Revolutionary Guard and others.
Rebels fighting to topple Assad remain divided on whether a nuclear deal would benefit or hurt their cause.
For many, an easing of Western pressure on Iran means Tehran would have a freer hand in the region. Nizar al-Hrakey, a member of the Syrian National Coalition and the group's representative in Qatar, compared it to the Russian-U.S. deal to try to rid Syria of its chemical weapons stockpile rather than carry out military strikes.
But Kamal Labwani, a veteran Syrian opposition figure, said Iranian concessions to the West means "total surrender," adding he hoped it would lead to a more sidelined role for Iran in Syria.
Associated Press writers Zeina Karam in Beirut and Ian Deitch in Jerusalem contributed to this report.