THE world has been given a stark warning that Iran is within two to three years of producing its own nuclear weapons.
Its controversial underground facility for enriching uranium at Natanz in central Iran will then be fully operational, and Iran has stockpiled enough unenriched uranium for 30 to 50 weapons.
The disturbing alert comes from the London-based International Institute for Strategic Studies (IISS), a prestigious think tank, which said "now is the time" for the world to act.
It says Iran's nuclear threat is more imminent than was suggested last June by John Negroponte, head of national intelligence for the US. He said Tehran might be able to build such weapons in four years.
Most concern is concentrated on Natanz, a small mountain town in central Iran, known until recently for its bracing climate and fruit orchards.
But deep underground is a facility which is being stacked with a massive array of centrifuges for enriching uranium to bomb-making capacity, although President Mahmoud Ahmadinejad insists the country is only developing nuclear power. The facility was Iran's best-kept secret until late 2002, when its existence was revealed by an Iranian exile group.
Now it is the focal point of intense satellite surveillance and every other type of hi-tech eavesdropping the US and Israel can muster. Neither government has ruled out entirely the option of destroying Natanz by direct attacks, possibly nuclear ones.
Mark Fitzpatrick, a senior fellow at the IISS, says there is no justification for allowing Iran to become "a little bit pregnant" through a small amount of enrichment because once it has mastered the technology "it will be able to replicate it somewhere else in the country" where the sites could not be found by outsiders.
"Now is the time for the world to agree on a strategy to preclude Iran from reaching that point," Fitzpatrick said.
"The world is not saying Iran cannot enjoy its inalienable right to civilian nuclear energy. Even President George W Bush has acknowledged this right. The issue is the fuel-cycle technology that can be used to make nuclear weapons. Neither is Iran being asked to forego this technology forever. The EU offered in August last year to review the suspension at some future date when Iran had regained the world's confidence in its peaceful intentions."
Last week, according to diplomats in Vienna, Iran began installing piping and electric cables at Natanz, with hundreds of technicians and construction workers "working feverishly" at the site.
The move marks an escalation of the confrontation between Tehran and the world's major powers over the Islamic republic's nuclear programme.
Despite Tehran yesterday allowing six envoys to visit nuclear sites as part of an effort to show "transparency" over its disputed atomic project, the US has said that simply putting Iran's nuclear activities on display would not build confidence abroad.
The West is also concerned about the nuclear reactor Iran is building at Bushehr, from which weapons-grade plutonium could eventually be extracted. But the US has to tread warily to avoid a direct confrontation with Russia because the reactor is being built by Russian technicians with Russian expertise.
According to Dr John Chipman, director of the IISS, Iran is on track to complete its goal of producing 3,000 centrifuges by the end of next month or shortly afterwards. He added that a significant proportion of the centrifuges were obtained on the black market from Pakistan. Getting them to function could take another year.
International worries over Iran's nuclear intentions have been increased by the belligerent and uncompromising noises coming from Tehran, especially the hard-line Ahmadinejad, who sees the acquisition of nuclear power as proof of Iran's international status.
Last Thursday, Ahmadinejad said that Iran will celebrate the "stabilisation" of its nuclear programme as early as this week - thought to refer to the installation of the new centrifuges. Diplomats say Iran is ready to begin its installation to produce enriched uranium after completing work at the underground facility. Their reports are based on findings by UN nuclear agency inspectors who visited Natanz last week.
In introducing its annual Military Balance, an assessment of world armed forces, the IISS said: "If and when Iran does have 3,000 centrifuges operating smoothly, the IISS estimates it would take an additional nine to 11 months to produce 25kg of highly enriched uranium, enough for one implosion-type weapon. That day is still two to three years away."
Meanwhile, it said, Iran has stockpiled 250 tonnes of uranium hexafluoride (unenriched uranium), enough, when enriched, for 30 to 50 weapons.
The West is worried that religious fundamentalist countries such as Iran would be more likely to launch a nuclear attack than their secular counterparts because they would not fear their own destruction.
Jeffrey Herf, a terrorism expert and history professor at the University of Maryland, said: "Should a radical Islamic group or state come to possess weapons of mass destruction and the means to deliver them, there is no reason to assume that the prospect of nuclear retaliation by the United States would deter war. This is so because, in their view, their own death is a prelude to certain entry to a better life in the heavenly paradise to come.
"In contrast to the communists during the Cold War, who wanted to change, not depart from this world, the cult of death and martyrdom of the terrorists inspired by Islamic fundamentalism raises deeply troubling questions about the prospects for peace and security in the future."
That was the fundamental weakness in the strange remarks last week by French President Jacques Chirac - hastily retracted - that one or two nuclear weapons in Iran's hands would be "not very dangerous" because Iran would know that if it used a nuclear weapon against Israel "it would not have gone 200 metres into the atmosphere before Tehran would be razed to the ground".
Fitzpatrick, of the IISS, says: "I assume that the military option is one the defence planners are looking at. But Washington is also looking to the UN and financial sanctions, and is not giving up at this moment. But pressures will increase."
However, there is a chance that Iranians themselves will stop the race for nuclear capability.
"There are signs that political and economic pressure is having an impact in Tehran," said John Chipman, the institute's director. "But whether the international debate will lead to a suspension in the enrichment programme that would provide the basis for resumed negotiations remains to be seen."
On Friday Iran appeared to be showing flexibility over UN inspections. It denied that it had barred international inspectors from the underground facility and was confining them to a small above-ground research centre.
But observers are more suspicious. Iran has played games before with the international inspectors.
