The last time Iran's nuclear envoys held talks with the U.S. and other world powers, the negotiations limped along until a parting shot by the Islamic Republic: Its labs boosted the enrichment levels of uranium in reply to demands for a full-scale freeze.
Since then, the standoff has only become tenser. The European Union on Monday joined the U.S. with new sanctions targeting Iran's critical oil exports. Authorities in Tehran fired back with another threat to block tankers in the Persian Gulf _ even while offering to restart international talks after a one-year gap.
Yet one thing hasn't changed since the last round of meetings in January 2011. The chances of Iran agreeing to stop enriching uranium _ the core dispute between Tehran and its foes _ still appear slim.
Iran portrays its ability to make nuclear fuel as akin to a patriotic cause: showcasing the country's technological advances, elevating its international stature and proudly defying Western nuclear controls like other nations in the past _ including North Korea since the 1990s and China in the 1960s.
Iran strongly denies that it seeks nuclear weapons and says it only wants to enrich uranium to fuel reactors for energy and research. But Iran's Supreme Leader Ayatollah Ali Khamenei has linked control of the entire nuclear cycle to part of Iran's "national identity."
"Iran's right for uranium enrichment is nonnegotiable," said conservative Iranian lawmaker Ali Aghazadeh. "There is no reason for Iran to compromise over its rights. But Iran is open to discussions over concerns about its nuclear program."
The bloc on the other side of the negotiating table _ the five permanent Security Council members plus Germany _ has not publicly spelled out any clear strategies if talks resume in Turkey as a proposed venue. It's highly unlikely, however, that they would back off the insistence that Iran suspend uranium enrichment, which Washington and others fear could lead to weapons-grade nuclear material.
The potential dead ends are clearly marked even before any agreement to reopen dialogue.
Iranian officials hammer the point that halting uranium enrichment is off the agenda. Some in the West, meanwhile, question whether Iran's outreach is simply another tactic to buy time for its nuclear program under pressure from cyberattacks and targeted killings that Tehran has blamed on Israel and its allies.
In Paris last week, French Foreign Minister Alain Juppe said the European Union has made specific proposals for dialogue with Iran, but "unfortunately the country has not committed in a transparent and cooperative way in this process of talks."
On Monday in Brussels, the EU's foreign policy chief Catherine Ashton urged Tehran to offer "some concrete issues to talk about."
"It is very important that it is not just about words; a meeting is not an excuse, a meeting is an opportunity and I hope that they will seize it," she said as the EU adopted its toughest measures yet on Iran with an oil embargo and freeze of the country's central bank assets.
Iranian lawmaker Aghazadeh snapped back: "The West is not seeking a genuine dialogue."
"It's unlikely that any new round of talks will bring any understanding," he added. "There is lack of trust on both sides. Iran won't retreat from its position."
The situation carries strong echoes the last talks in January 2011. When the main talks foundered, Brazil and Turkey tried their hand by reviving proposals to provide Iran with reactor fuel rods from 20 percent enriched uranium in exchange for suspending the enrichment work.
It fell apart when Iran pushed ahead with a pilot program to make its own 20 percent enriched uranium. That's still far below the level needed for a warhead, but it boosts Iran's stockpile of higher-grade nuclear material and was seen as a powerful snub to Western demands.
In a news conference on Saturday, Iran's Foreign Ministry spokesman, Ramin Mehmanparast, used the word "justice" to describe what Tehran hopes to achieve from any possible talks.
It covers a lot of ground in explaining Iran's views.
Tehran considers its nuclear program as fully within U.N. rules _ which permit enrichment with oversight _ although U.N. watchdogs and other question how much of Iran's work is secret. Tehran also seeks to shift the nuclear spotlight onto Israel, which is believed to have an atomic arsenal despite its policy of neither confirming nor denying its military capabilities.
But, above all, the Islamic Republic sees its nuclear advancement as an integral part of its self-declared goal of becoming the Muslim world's answer to Western military and technological dominance.
Iran has announced sweeping plans for upgrades to its armed forces, including new warships and surveillance drones similar to the unmanned CIA spy craft captured last month. Iran's state media has claimed aerospace engineers have launched objects into orbit and are working on sending an astronaut into space.
"The nuclear program is a huge part of what's shaping Iran's world view," said Mehrzad Boroujerdi, an Iranian affairs expert at Syracuse University. "Khamenei sees it as part of his legacy. In a way, it's like the nationalization of the Suez Canal for Egypt. It's a defining issue and one of major national importance."
It also is one of the few patches of common ground in a country deeply divided since the clashes and crackdowns after President Mahmoud Ahmadinejad's disputed re-election in 2009. Even opposition groups that rail against the ruling theocracy often support the nuclear program as a point of pride.
"The issue is protecting national interests," said Iranian political analyst Davoud Hermidas Bavand.
Yet he believes that talks _ even if they at first appear ill-fated _ are the only option to avoid deeper tensions that could lead to a military conflict in the Gulf.
"Talks offer a window to get out of the current impasse," he said.
The question still circles back to whether it could bring some concessions from Iran on uranium enrichment.
Meir Javedanfar, an Iranian-born analyst based in Israel, described Khamenei as stuck between "Obama and a hard place."
Khamenei cannot easily roll back the Iranian nuclear program, but is hit with increasing blows from sanctions that have isolated and eroded Iran's economy.
"Should he ignore it, the Iranian economy, the health of which is crucial to the survival of the regime, could collapse," he wrote in a Sunday commentary.
Keeping the ruling system in place, however, could also drive Iran's nuclear advances closer toward weapons, others contend.
"They perceive the whole nuclear issue as an insurance policy of sorts," said the analyst Boroujerdi. "There are those who say, 'If we are a nuclear power then the West wouldn't dare touch us.' And this, in their mind, helps ensure the survival of the system."
Associated Press writer Ali Akbar Dareini in Tehran, Iran, contributed to this report.