The controversy over Iran's nuclear program continues, with the IAEA board meeting in Vienna and Iran apparently arresting someone for spying on their classified--but peaceful--nuclear activities. Meanwhile, in a lengthy article on the history of Iran's nuclear efforts, the New York Times has asked what may be the most interesting question in the entire matter: why doesn't Iran already have nukes? Their answers shed useful light on the uncertainties involved but may risk getting lost in the details. A simple reality check is in order.
Few of us are in a position to assess directly the technical challenges facing Iran--assuming they are pursuing nuclear weapons and not merely protecting their own future fuel rights, as they have repeatedly asserted. The last sixty years, however, provide several useful data points for comparison.
It all started when the US created a nuclear weapon from scratch in three years, using 1940s technology. That required bringing together many of the smartest physicists in the world and building an industrial base that siphoned off a sizeable share of the country's GDP. They cracked the basic science and engineering problems, and they did it with slide rules and graph paper. This was a stupendous achievement, but I believe it's the wrong way to think about what Iran is doing. Trinity and Hiroshima established the critical "existence proof" of nuclear weapons, and a variety of other countries have replicated this feat without resorting to quite the scale of effort necessary the first time.
The USSR provides a much better comparison, though scale limits its usefulness. Russia developed and tested its own bomb within 7 years from the start of the Manhattan Project, in the face of determined US efforts to deny them this technology. While they were able to marshal the scientific and physical resources of an enormous country for the effort, they also benefited from a broad flow of scientific and engineering data obtained by their espionage on the Manhattan Project. This is thoroughly documented in an excellent book by Richard Rhodes, "Dark Sun."
Britain and France also developed nuclear weapons, but their programs seem less comparable to Iran's. The UK actively participated with and was assisted by the US, while France had an active nuclear science program going back to the end of World War II--even though it took until 1960 to explode their first bomb. China and India may be closer to the mark, but both benefited from significant technology transfer. The recent example of Pakistan, though, seems applicable on many grounds.
In 26 years from inception to first test, a country roughly comparable to Iran was able to develop the required infrastructure, solve all the associated technical and logistical challenges, and explode a Hiroshima-style bomb based on the enriched Uranium path that is the current focus of international concern in Iran. They did this with a bit of foreign assistance and some smart scientists, including the now-infamous A.Q. Khan. In fact, Pakistan is thought to have had the ability to produce a bomb at least a decade before its first test in 1998. That brings the timeline for the core of their program down to about a dozen years.
Iran's case is unique in several respects, but the similarities are real, and it enjoys important advantages over Pakistan in terms of finance and in not being a pioneer, even within its class of medium-large developing countries. So while experts may argue about precisely when Iran might be able to build a nuclear weapon, history suggests that the smart money would bet on a decade or less. At the same time, careful analysis of the factors that have prevented Iran from succeeding where Pakistan did might point the way towards keeping things that way.