Some western powers once thought Iran could develop an atomic bomb by 2010. However, the US, Israel and many Iran watchers believe Tehran's nuclear efforts have slowed considerably, largely due technical problems.
Iran's nuclear program is moving slowly, which has many in the west relieved
Iran has invited foreign diplomats, including Russia, China and several EU countries, to tour its nuclear facilities this weekend, including a nuclear enrichment facility and a plutonium-producing heavy water reactor.
While Tehran is eager to show off what it says is its peaceful nuclear energy program, US agencies, an outgoing Israeli intelligence leader and many Iran experts believe Tehran's nuclear ambitions -which many suspect include making a bomb - have been set back by two years or more due to technological glitches, tough sanctions and personnel problems.
"Every time before a big meeting, Iran tries to give a sign of good faith," Oliver Schmidt of the German Council on Foreign Relations told Deutsche Welle, referring to the planned Jan. 21-22 meeting in Turkey between Iran and six major powers.
But when it comes down to actually negotiating about their policies "they usually don't give in that much," he said. The United States, France, Germany and Britain, countries which have been highly critical of Iran's nuclear ambitions, were excluded from the guest list.
But the representatives from the six permanent members of the UN Security Council plus Germany who will be sitting across the table from Iranian officials in Istanbul later this month might be breathing easier since the widely held fears about the imminent development of an Iranian nuclear bomb have eased.
The nuclear facility of Natanz will be on the tour this weekend
The US now believes that the country would not be able to produce a nuclear bomb until at least after 2012.
"We've got more time than we thought," CIA Director General Michael Hayen told Reuters. Possible military action against Iran has been effectively postponed "until the next presidential term."
The shift of opinion in Israel, which sees a nuclear-armed Iran as a mortal threat, has been even more significant. The Israeli government once thought Iran's nuclear capabilities were advanced enough to produce a bomb within a matter of months.
However, the outdoing director of the Israeli intelligence agency Mossad, Meir Dagan, has said that "because of measures that have been employed against them," Iran would not be able to build a bomb for at least four years.
"But we have to be careful about these kinds of estimates, because there could always be surprises in one direction or another," Oliver Thraenert, an Iran expert at the German Institute for International and Security Affairs, told Deutsche Welle. "But both Israel and Washington believe that the window of opportunity is bigger now."
The bite of sanctions
Those measures referred to by Meir include US, EU and UN sanctions, including a tightening noose around Iran's oil production. US President Barack Obama signed legislation last July imposing sanctions on any company that invests in Iran's oil infrastructure or sells refined products to the country.
US Secretary of State Clinton says sanctions are working
Other measures in place include a range of economic, high-technology and military sanctions, pressure on banks and insurers to sever ties with Iranian entities linked to the nuclear program, and a freeze on the assets of various high-ranking officials.
"The sanctions, which always take a while to start working, are making it difficult and expensive for Iranians to go forward, and have been costly in terms of domestic politics," Sharam Chubin, a senior associate in the Carnegie Nuclear Policy Program, told Deutsche Welle, "The elite in the country are asking if there are not more intelligent ways to do this."
"Will sanctions get Iranians to stop enrichment?" he said. "No, but it has slowed them down, especially given the fact they have a program thrown together from so many sources, including the black market."
Another factor behind the nuclear difficulties has been the Stuxnet cyberweapon used against Iran in late 2009 and early 2010, a computer virus which may have destroyed as many as 1,000 Iranian nuclear-fuel centrifuges in the fuel enrichment plant at Natanz.
The Stuxnet attack is estimated to have disabled some 1,000 centrifuges
The virus targeted industrial control systems that ordered converters to drastically increase and then reduce the speed of the centrifuges. The changes either put the equipment out of commission or greatly reduced its output.
"If (Stuxnet's) goal was the destruction of a limited number of centrifuges and to set back Iran's progress, it may have succeeded," said a report written by the Institute for Science and International Security.
It is still not known who was behind the cyberattack, although many suspect the US or Israel or perhaps China or Russia.
Personnel problems have also hampered Tehran's nuclear ambitions, including defections of nuclear scientists and separate bomb attacks that killed two Iranian nuclear scientists. Iranian officials have accused the West and Israel of being behind the assassinations.
The setbacks have lowered the likelihood of military action by Israel, an idea that did not seem far-fetched to many just a year ago. Some Israeli officials had felt as late as last spring that it might be necessary for Israel to attack Iran's nuclear facilities by the end of 2011.
But journalist Jeffrey Goldberg, who has written about an imminent "confrontation" between Iran and Israel for The Atlantic magazine, said an Israeli official told him the chances of an Israeli strike on Iran in the next year are below 20 percent.
Washington has not ruled out the possibility of military action, either, although some analysts believe the sabre rattling has been more of a pressure tactic on both Iran and even on Russia and China than a real consideration, since an attack on Iran would have unforeseen consequences in a very volatile region.
And some think officials and analysts are being too sanguine about Iran's program. Israeli Prime Minister Benjamin Netanyahu has called on sanctions to be strengthened further and wants "a credible military option" to be supported by the international community.
Iran says the West is out to assassinate or kidnap its nuclear scientists
The challenge for the US, the EU, Israel and other allies will be continuing progress in what will likely prove a diplomatic marathon with Iran. Britain, France, China, Russia, the United States and Germany will likely continue their two-pronged approach with Iran during the two days of talks later this month - seeking more diplomatic engagement while threatening even tougher economic sanctions.
But expectations are low for substantial progress in the near future and US Secretary of State Hillary Clinton has said "I don't think we can put timetables on it." No real progress was made when talks resumed in Geneva last month for the first time in more than a year.
And while officials and analysts are surely welcoming the additional breathing room they have due to Iran's nuclear troubles, the process is by no ends coming to an end.
"I am a bit more optimistic now that the nuclear program has been slowed somewhat," said Iran-watcher Thraenert. "But I still don't see a political solution at the moment."
Author: Kyle James
Editor: Rob Mudge