Brave new world revisited

Iran claims to have enriched uranium.

UPDATE: From the NYT coverage –

David Albright, president of the Institute for Science and International Security, a private research group in Washington, said that the announcement that Iran was able to produce that level enrichment of enrichment had been expected, but that the quantities were probably very small.

“They need to learn a lot more to produce it in significant quantities and they need to build a lot more centrifuges,” he said.

Frankly, I don’t understand this comment. Why would it take Iran so long to do something in 2006 that the US was able to do relatively rapidly in 1942-44?