The Iranians tricked us...

The former deputy director of the IAEA talks about Iran...

SPIEGEL: You sound worried. Is Tehran really on a direct path to becoming a nuclear state?

Heinonen: It's undeniable that Iran's nuclear program is far more advanced than it was in 2003, when the discovery of the Natanz facility brought it to the IAEA's attention. At the time, uranium enrichment tests were being carried out in secret on a small scale. But at the end of 2003, the Iranians admitted they were also planning to set up a heavy-water reactor in Arak to generate plutonium.

SPIEGEL: In other words, the other ingredient you need to create either nuclear power or an atom bomb.

Heinonen: Iran always told us it was only interested in the civilian uses of atomic energy. I've always had my doubts about that, more so now than ever.

SPIEGEL: Why don't you say what your former boss, Mohamed ElBaradei, said: That you haven't found the so-called "smoking gun" -- i.e. clear proof that Iran is developing nuclear weapons?

Heinonen: Before opponents of the Iranian regime exposed the existence of Natanz, those in power in Tehran had kept parts of their nuclear program secret for two decades. Today the facts are as follows: The conversion plant in Isfahan has produced 371 tons of uranium hexafluoride. Some 8,000 centrifuges in Natanz are being used to enrich this raw material. In February 2010, Iran began increasing enrichment to 20 percent. That's a significant step closer to making an atomic bomb because it takes only a few months to turn that into weapons-grade material. And at the beginning of this year, Fereydoun Abbasi was appointed the head of the atomic energy organization in Tehran ...

SPIEGEL: ... a scientist who has been on a UN list of suspected bombmakers since 2007, whom a UN Security Council resolution forbids from traveling abroad, and who just barely survived an assassination attempt in Tehran 10 months ago suspected to have been carried out by the Israeli secret service.

Heinonen: In early June, Abbasi announced that Iran was moving the 20-percent enrichment of uranium from Natanz to Fordow, where they are tripling production. Incidentally, the construction of the Fordow plant near Qom was so shrouded in secrecy that the Iranian authorities first admitted it existed less than two years ago.

SPIEGEL: And none of this makes sense for a civilian nuclear program?

Heinonen: You don't need 20-percent enriched uranium to generate electricity for light bulbs. And, in any case, the produced volumes far exceed what Iran might possibly need for its research reactor. What's more, Tehran has announced that it intends to build 10 more enrichment plants, and Iranian experts have conducted experiments with neutron sources and highly explosive detonators that would only make sense for military applications. They're also making progress at the heavy-water reactor in Arak, so much so, that by 2014 they'll have enough plutonium to build an atom bomb.

SPIEGEL: So you think Iran will declare itself a nuclear power in 2014? Will the leaders of the theocracy already have a working atom bomb by then, or will they only threaten to build one?

Heinonen: I don't know. I am, however, convinced that Tehran will reach the "break-out capabilty" -- in other words, the capacity to produce weapons-grade uranium -- as early as by the end next year. In that sense Iran aims to be a virtual nuclear power with the capability of producing the ultimate weapons at any time.