Although Hall's information was helpful to the cause, the most influential of the atomic spies was Klaus Fuchs.

They have recently offered a 10 1/2-minute segment of videotape with a translated transcript, supposedly the basis for chapter 7, the one on atomic spies.

If you are going to pretend to be an atomic spy, it helps to know how an atomic bomb is made.

Assume that he conspired to deliver even inconsequential classified information about nuclear weapons research, would that define him as an atomic spy?

"Any word yet from Ames about that atomic spy?"

The Soviet Union had other atomic spies but none with Mr. Fuchs's scientific expertise and access to key information.

The members of Congress debating the bill feared that "atomic secrets" were being systematically stolen by Soviet atomic spies.

Not that it's easy to be an atomic spy, given the technical nature of what you're looking for.

Why wasn't the atomic spy Klaus Fuchs picked up much earlier, for example?

The Manhattan Project operated under a blanket of tight security, but Soviet atomic spies still penetrated the program.