In response to:

He Changed History from the April 9, 2009 issue

To the Editors:

In my article on A.Q. Khan [“He Changed History,” NYR, April 9], he should not have been referred to as a “nuclear physicist” in the caption to the photograph of him. As I said twice in the article he was a “metallurgist.” His function in the Pakistan program was to supply the plans and knowledge for the Pakistanis to enrich uranium using centrifuges.

These centrifuges were traded, no doubt with government complicity, to the North Koreans for missiles and very likely to the Chinese for plans about how to use this uranium to make a nuclear weapon. Ultimately Khan sold both these plans and the centrifuge designs to places like Libya. The Libyans eventually turned over the bomb plans to the US. They are classified but at least the responsible people know what they are.

On the other hand, we do not know what Khan turned over to either the Iranians or the North Koreans. The North Koreans have so far chosen the plutonium route at their Yongbyon reactor and it is not clear if anything that Khan turned over was of use to them. The Iranians have chosen the uranium route, using centrifuges for enrichment at their facility in Natanz, as well as the plutonium route at their reactor at Arak in central Iran. Whether or not they have the plans for a nuclear weapon I do not know, but my guess is that they do.

Jeremy Bernstein
Aspen, Colorado

This Issue

May 28, 2009