Zimmerman replies: Let me first apologize to Lynn Eden for misstating the yields and burst heights of the nuclear weapons she compares in her first chapter. I had computed several cases, and unwittingly carried the wrong printout from table to computer. However, Eden’s figures strengthen my contention that she compared apples with oranges.
According to the standard work on the effects of nuclear weapons, 1 blast effects are comparable for weapons at burst heights h 1 and h 2 such that (h 1/h 2) = (W 1/W 2)1/3, where W 1 is weapon yield. Thus, an appropriate altitude for the 300-kiloton detonation should have been about 5000 feet for it to be compared with the Hiroshima bomb, not 1500 feet. Scaling for thermal radiation effects depends on the distance between the fireball and the exposed ground, because of both the inverse square law and any atmospheric absorption.
John G. Lewis and I are in near-perfect agreement. I stated that there was no conspiracy to exclude fire damage from targeting calculations; he as an insider confirms that. I take his point that there were too few weapons effects tests. Experiments with multiple synergistic effects might have provided early on the tools to compute the ignition and spread of fires. After the 1963 Limited Test Ban Treaty, atmospheric testing ended, and no further large-scale experiments could be done. Even during the days of atmospheric testing, effects shots always took a back seat to the Atomic Energy Commission’s testing to improve the weapons themselves.
Harold Brode probably knows more about nuclear weapons effects than any other person alive. But I challenge his comment that my description of the effects of weapons in very different yield categories was misleading. I clearly indicated that I was referring to simple rules of thumb about nuclear weapon phenomenology as made by the effects community. I am aware that even a very low yield, “enhanced radiation” weapon has significant blast effects. 2 Nevertheless, it is appropriate to first order to think of 20-kiloton devices as inflicting damage at greater ranges by blast than by mass fires, and to think of very large weapons as primarily wide-area incendiaries. It is also well known that fires can be started by broken gas mains, downed electrical lines, defective bakery ovens (London, 1666), and cows upending lanterns.
Brode also confirms my belief that there was no government conspiracy to prevent fire damage from being included in damage predictions. In my review, I said that I thought Eden perceived a conspiracy, but that I saw none. I do not understand why Brode and Lewis suggest I endorsed a conspiracy theory.
In retrospect perhaps I should not have called Eden’s book a diatribe nor indicated that she saw a conspiracy. But how could a sympathetic and knowledgeable reviewer come away with such an impression? It lies in the text of chapters 8, 9, and 10. There, Eden shows the interplay of Brode’s system for predicting fire vulnerabilities and damage with the work of the fire research community. On page 236, she quotes Brode as saying that fire predictions could have been incorporated into targeting calculations in 1948, 1954, or 1958. But they were not. Why not?
Eden gives a partial answer, unflattering to the targeting community, which is said to have asked, “Were the differences in resulting damage sufficient to warrant the time and cost?” (p. 248). Always, Eden indicates, decisions on incorporating fire damage were put off “for probably another year. They wanted some additional work done” (p. 251).
On page 261 Eden describes a 1988 letter to Brode that indicated fire damage predictions were still a long way off—even though Brode had convincingly demonstrated that the technique worked well enough. She quotes Vice Admiral Michael Colley (p. 272) as saying, “We [didn’t] need the fire thing to help us, because it’s already a very, very devastating attack.” She again quotes Colley that “fire is gravy. Whatever you can get from fire just makes everything worse.”
By choosing such quotes from the targeting community, Eden gave me the impression that scientists like Brode and Theodore Postol were the heroes, while the targeting agencies were scoundrels, not wishing the world to see the additional horror of nuclear fires. She certainly delivers an indictment of the damage-computation community.
Finally, the civilian cases, which Eden treats brilliantly, are not parallel to the nuclear one. Each civilian case involved only one or two events, each was resolved swiftly, and the new information was rapidly incorporated into the relevant organizational frames. In contrast, Eden shows that the nuclear targeting agencies did not change for five decades, even when new and good information was provided.
