Science: Atoms at Retail

So long as U-235, the explosive isotope in natural uranium, was hard to get, only the biggest powers could afford nuclear bombs. Now everybody—Mao, Castro, Nasser or whoever—may soon be able to have a bomb of his own. Previously, U-235 was almost impossible to separate from nonexplosive U-238, except with great expense and difficulty. But, said Tennessee's Democratic Senator Albert Gore, member of the Joint Committee on Atomic Energy, last week: "recent advances in [centrifuge] technology have now brought the capability of producing weapons-grade material within the reach of not just a few but of many nations."

This was no surprise to...