Analysis: Fuse to Iran’s nuclear timebomb is longer than we might think

In 1992, Benjamin Netanyahu, then an Israeli parliamentarian, warned that Iran was between three and five years away from producing a nuclear weapon.

The threat, he insisted, had to be “uprooted by an international front headed by the United States”.

Fast forward two decades. Mr Netanyahu, now Israel’s prime minister, is warning that the Islamic republic will be on the brink of developing the bomb by the middle of next year.

So how far is Iran from getting the bomb? Timeline estimates are fraught with uncertainty because it is not known how advanced the Iranians may be in their suspected nuclear bomb research.

Most experts believe it would take Iran at least two years to assemble a single nuclear-tipped missile, if it decided to do so.

Some, though, put it at just over half that time while US officials estimate Iran would need 12 to 18 months to build an atomic weapon.

Mr Netanyahu’s calculations are seemingly based on when Iran could have enough medium-enriched uranium to make a sprint to produce sufficient weapon-grade material for one bomb.

With provisos, many analysts agree with him that Iran could be in that position by next summer, although others say Tehran could need even less time.

But even if Iran makes a dash to enrich its uranium stockpile, it would probably need another six months to assemble a “crude nuclear device”, said Mark Fitzpatrick, a senior non-proliferation expert at the International Institute of Strategic Studies in London.

“And to produce a nuclear weapon that could be deliverable by a ballistic missile would take at least another year,” he added in an interview. “So the total time is at least two years.

“And that is only for one weapon. It would be foolhardy for Iran to undertake the risk, only to produce one nuclear weapon.”

Israel, the Middle East’s sole – if undeclared – nuclear-armed superpower is thought to have as many as 200 nuclear warheads.

Mr Fitzpatrick’s timeline, based on a review of open-source materials and discussions with government experts, tallies with a recent report signed by nearly three dozen high-ranking national security officials in the US.

They believe Iran would need between one and four months to produce enough weapons-grade uranium for a single nuclear device.