An Insider’s Account: Seymour Deitchman

An Insider’s Account: Seymour Deitchman



I have perused the JASON report evaluating possible use of nuclear weapons against North Vietnamese and Viet Cong forces in the Vietnam War during the 1960s, and also examined what materials I have in my files at home that bear on the 1966 JASON summer study during which the report was generated and searched my memory carefully. I caution readers about memory, however. Events, even those that were vital and important at the time, do tend to fade, collapse into each other, and get distorted in the recollection after nearly 40 years, so I cannot guarantee that all I am about to note is totally accurate. But the memories from that period are vivid, still, so I hope what I am about to recount is not too far off from what actually transpired.

First, it is worth a note on how the study was generated, and describing my involvement. As is well known from other sources, JASON was at the time a self-starting organization (I assume they still are, but I have had no contact with them for at least two decades). They were an organization highly respected in the Defense Department, and their scientific inputs on key issues were much valued. At the time, they were supported by ARPA (the Advanced Research Projects Agency, now DARPA, the Defense Advanced Research Projects Agency), which set aside an amount of money to cover their activities for each year. Administrative support and technical backup were provided by the Institute for Defense Analyses (IDA), a federally funded studies and analyses center under contract to the Defense Department. Typically, the JASONs were briefed at a few meetings during the academic year on major issues and problems the Defense Department faced that the Department judged could benefit from sound scientific advice and in which JASON expressed interest, and they decided, on the basis of the briefings and their judgments about where they were interested and could make a useful contribution, what they would work on during a summer study that would last about 6 weeks.

At the time of this summer study, I had just returned to IDA from a two-year leave of absence during which I was Special Assistant for Counterinsurgency in the Defense Department, reporting to Harold Brown, then the Director of Defense Research and Engineering. My major responsibility during those two years had been the establishment of a research and development program to support the efforts of U.S. forces in Southeast Asia. I had just returned to IDA in January or so of 1966, when JASON started to think about their next summer’s work.

U.S. participation in the Vietnam War having been in full motion by then, and the university community having been rising in protest against the war effort, the JASONs thought they had a contribution to make. Specifically, as I recall, they were troubled, as were many Americans, about the seemingly endless bombing of North Vietnam and whether it was accomplishing anything. They hoped that they could help the nation find a way out of the stalemate that the bombing represented, and thought to use the coming summer study (1966) to explore means to do that. With the help of George Kistiakowsky, they inquired of Secretary of Defense McNamara whether that would be welcome, and he agreed. John McNaughton, then the Assistant Secretary of Defense for International Security Affairs, was an important contributor to Mr. McNamara’s development of the war strategy, and I believe that he likely acted as an intermediary in this exchange, as we briefed him on the study results afterward, before briefing Mr. McNamara.

Since I had recent experience and association with the management of the war effort in he DOD, I was a natural IDA staff member to work with JASON, to provide them technical support and input on the study. The study involved a preliminary meeting during the Spring of 1966 at a girl’s school in Massachusetts, where the general plan for the summer study (which took place at the University of California, Santa Barbara campus, in a dormitory building that was empty for the summer) and its topics were worked out. As I recall, there were to be three sub-studies: one, evaluating whether the bombing strategy, and the war of attrition strategy more broadly, were accomplishing what they were intended to accomplish; a second, whether it would be possible to devise a barrier to infiltration of people and supplies from North Vietnam to the battlegrounds in the South, and thereby ease the pressure to bomb the supply sources in the North itself; and a third, whether it made sense to think about using nuclear weapons to close off the supply routes, which had to go through a few difficult mountain passes to reach the Ho Chi Minh trail through Laos over which the supplies and people moved.

I don’t remember much of the genesis of the nuclear weapons sub-study (I will return to that in a moment). My attention was given to the other two aspects of the overall study. In support of the question of whether the strategy was working, I do remember contributing a short paper that showed that we could not win the war of attrition that was our fundamental strategy because, since they initiated most of the actions, the North Vietnamese and Viet Cong could control their attrition and keep their recruitment in balance with it and with the size of their military age cohort. Most of my attention throughout the study was given to the barrier issue, however, since I was familiar with all of the programs and machinery that could be brought to bear on it. I remember that I spent an afternoon, at the girls’ school, with 5 of the JASONs (Fred Zachariassen, George Zweig, Henry Kendall, and two others whom I don’t remember), during which we devised the basic scheme for what later became the “Air Supported Anti-Infiltration Barrier,” reported in IDA report S-255 of that name. Then, at the summer study main session, I spent most of my time on that issue, and helped write the report describing the supply routes and the proposed barrier system design in detail. (I thought I had a copy of this report, but can’t find it. I believe it was declassified about the time I retired from IDA in 1988. The barrier report’s conclusions are described briefly in the Pentagon Papers (pp 506-509 of the Bantam Books paperback edition), but the richness of the JASON detective work that scoped out the nature of the Ho Chi Minh trail system for the first time, so that the barrier could be designed to work against it, is left out of the Pentagon Papers’ brief excerpt.).

I’m not sure whether the issue of using nuclear weapons in Vietnam was raised by Mr. McNamara or Mr. McNaughton in the preliminary discussions, but there had been enough talk around the Pentagon about using such weapons that they may very well have raised the issue as part of their interest in agreeing to support JASON’s proposed study. In the circumstances of how this study began and was defined, I can’t imagine that JASON would have volunteered to study that issue unless it had been spoken of seriously in some venue that made it a topic of concern. Knowing how he worked, I would judge that if he raised it, Mr. McNamara would have said, “There has been some talk about using tactical nuclear weapons to close the passes into Laos; tell me what you think of the idea.”

The passes had been viewed as especially troublesome. As I recall, the Mu Gia pass, through which a large fraction of the reinforcement and supply moved, was said to have a roadway carved out of a steep hillside, much like the road through Independence Pass southeast of Aspen, Colorado. This was a particularly difficult bombing target for the technology of the day, and although the general area of the pass was bombed heavily and incessantly, it was hard to hit and collapse the road itself. The North Vietnamese rapidly repaired any damage and the flow of people and supplies through it was almost uninterrupted. Frustrations such as this, combined with the sparse population in such areas, made the passes appear to be especially attractive targets for tactical nuclear weapons.

In that connection, I do remember at first hand that there had been not infrequent talk among some of the military people involved in planning the war effort, with whom I had contact, that “a few nukes” dropped on strategic locations, such as the Mu Gia pass through the mountainous barrier along the North Vietnamese-Laotian border, would close that pass (and others) for good. That, it was postulated, would force the North Vietnamese supply route into the southern part of North Vietnam and across the Demilitarized Zone dividing North from South, and along the coastal plain and waters, where it would be much more accessible to counter-action. The subject came up often enough in my casual conversations about the war effort, although it was aside from my main effort of building an R&D program, that it could have originated at a high enough level to have captured the Secretary’s attention. But at this point you would have to consider that speculation on my part.

Although I was not involved in the Dyson group’s study, I did hear their briefing-it was the JASON pattern that all sub-studies were briefed to the entire JASON summer study group at the end of the study period. I remember being struck by the main conclusion, that if we started down that route we risked being hurt much more than the North Vietnamese and the Viet Cong, because I had been uneasy about the easy talk of using nukes right along.

The only thing I remember from the outbrief with John McNaughton was his unhappiness with the result of the study of the bombing and war of attrition strategy, that the data on enemy casualties and infiltration were so chancy and uncertain that he could not judge, based on those data, whether he had a war-winning strategy or not. (His reaction was not, “I’d better rethink our strategy,” but rather, “you haven’t been able to prove I have a winning strategy,” implying that the study had failed. That kind of response sticks in the memory.)

I was also in the debriefing of Secretary McMamara, with George Kistiakowsky and some of the other JASONs (I believe, Bill Nierenburg, Murph Goldburger, and Hal Lewis, for sure, and also Johnny Foster, who had by then become DDR&E (Director of Defense Research and Engineering), and possibly one or two others whom I don’t remember now). My recollection of that is, that the Secretary expressed great interest in the air supported barrier idea, since, as he remarked, all the expenditures on the bombing campaign, and R&D toward being able to bomb in all weather, did not seem to be producing results. The barrier idea was something new he could try, and he indicated that he was inclined to do so. I later flew up with him to attend a meeting at the Cape Cod house of Jerrold Zacharias, with some of the JASONs who had worked on the barrier part of the study, and after much discussion of possible North Vietnamese countermeasures he indicated that he liked the idea well enough to risk implementing it, even though we had told him it had about a one in twenty chance of success. (For a somewhat hostile rundown on this meeting and the background to it, see Science, Vol. 179, Feb. 2, 1973, pp 459 ff. There is a good description of the background to JASON in this article, however.)

I don’t remember any discussion of the nuclear weapons issue at the Pentagon outbrief or at the later meeting, although I can’t imagine that it didn’t come up, since it was part of the overall report. That lapse may be in part due to the way the Pentagon briefing went. As we started, prepared to brief him on all the study results, Mr. McNamara cut us off and commented that he had read the report, and he had some questions, whereupon he opened it to pages he had marked and we talked mainly about the barrier idea. So, if he had simply absorbed the results of the nuclear weapon part of the study and had no special questions about it, it may not even have come up.

I do remember, however, that when I returned to the Pentagon in the Fall of 1966, after Johnny Foster twisted my arm to come back and manage the ARPA program of R&D in Southeast Asia (known as Project Agile, and, at the time, “Remote Area Conflict,” which I changed to “Overseas Defense Research,” since the conflict was not remote for the people involved in it), I heard no talk at all of using nuclear weapons in the Vietnam conflict. Although I don’t know, I think it is reasonable to conclude from that that, if consideration had been given to the idea before the study, Mr. McNamara simply dismissed it as something not to think about seriously, and therefore the talk simply went away.

In sum, regarding the question at hand: Yes, there had been some kind of consideration of using tactical nuclear weapons to close the passes between North Vietnam and Laos, as a way of stopping troop and supply movement from the North to the South, informal as far as I know but possibly formal, and at high enough level to have made it a topic for the JASON study that was agreed with the Secretary of Defense. The results of the JASON study of the subject were known to the Secretary of Defense. To the extent of my personal knowledge, the talk of using nuclear weapons in that war stopped after the JASON report on the subject. To me it is a reasonable inference that the Secretary was troubled enough by the talk to have asked the JASONs to look at the question, or to have acquiesced in their proposal to look at it, and that after the study he put a stop to the discussion of it, or the topic went away because he refused to consider it. Therefore, in my view, the study had the desired effect.


On February 25, 2003, Peter Hayes conducted an email interview with Mr.. Deitchman on his account of the JASONs’ reports in 1966. The questions and answers follow:

Hayes:   The JASONs involved with the tacnuke study say that the genesis of their study was them overhearing loose military talk about “tossing in nukes.”
Deitchman:   Yes, but I don’t remember whether that led them to include it in the main summer study, or they simply tacked it on impulse – that is, I don’t remember whether it came up at the same time as the barrier and the analysis of the bombing. I thought it did, but couldn’t swear to it. There was lots of such loose talk.
Hayes:   This suggests an independent genesis for the tacnuke report that summer session. Is it possible they simply did it off their own bat and that it wasn’t part of a 3-pronged JASON summer session (barrier study, bombing study, tacnukes study), simply an “autonomous study?”
Deitchman:   In a sense it was all “autonomous,” as they had simply set the topics themselves, after talking with Sec. McNamara. I don’t know the extent to which the separate topics were discussed with him, as I got involved in it just after it was generated. I believe George Kistiakowski was one of the prime movers and the intermediary with McNamara, as he had been the President’s science advisor and had that entree.
Hayes:   Even if it was unconnected to the other two studies, presumably it had to be funded and cleared?
Deitchman:   JASON’s studies were funded as a block, and they chose the topics within the block each summer. They had to run them by the DOD, as there were briefings to be requested and authorized, etc. But I never knew of any that had been turned down (I believe there were some arguments with ARPA about their autonomy, later, but that was years beyond the dates of this study).
Hayes:   In which case, the tacnukes study was still part of the JASON bureaucratic process?
Deitchman:   Yes.
Hayes:   Would McNamara have therefore approved?
Deitchman:   Agreed to it, is more like the way to express it, and might have expressed interest in and encouraged it, or simply been permissive. My take on his personality is, it would have been the former.
Hayes:   So McNamara would have agreed to it as part of the summer session, even if the reason it was on the candidate list is because the 4 JASON scientists pushed it onto the list?
Deitchman:   Yes — as just noted.
Hayes:   Thus, assuming the JASON’s have their story straight, is the “complete” account of the tacnukes study origin is that the scientists volition intersected with McNamara/OSD’s needs?
Deitchman:   That is just the way to express it, I believe.
Hayes:   Do you know why the contract for the JASON study was to DAHC?
Deitchman:   Yes: ARPA had no DOD contracting office of its own. They used the army as contracting agent. The army had a contracting office at Huntsville, AL, whose purpose was to service ARPA contracts (in my time, and I joined ARPA shortly after this study)
Hayes:   DAHC stands for Department of the Army?
Deitchman:   I think so –the initials are obscure to me – I never thought to ask.
Hayes:   Or was that purely bureaucratic process?
Deitchman:   Yes, as just noted.
Hayes:   When would the summer study session have begun/ended?
Deitchman:   I don’t recall exactly. I remember spending a week touring California with the family before settling in at Santa Barbara, and that would have had to be after school ended. So I assume the study started in early July (1st or 2nd week) and ran until mid-August (6 weeks).
Hayes:   When would “candidates” for study been proposed in 1966?
Deitchman:   I think all that took place in February-March. The meeting at the girls school would have been late April/early May.
Hayes:   Does the fact that the sub-studies were briefed to the entire JASON study group at the end of summer mean that the other JASON scientists involved in the other two studies would have been at the briefing–if it occurred–on the tacnukes options study?
Deitchman:   Yes.
Hayes:   And as many of them are still with us, might recollect it?
Deitchman:   Hopefully.
Hayes:   What was the month/date of the summer session debrief?
Deitchman:   I don’t remember exactly, but would likely have been late August/early September. McNaughton didn’t waste any time getting the briefing
Hayes:   With regard to the JASON debriefing session with McNamara himself, you mention George Kistiakowsky and JASONs Bill Nierenburg, Murph Goldberger, Hal Lewis, and Johnny Foster as being there. Was he (McNamara) briefed on the tacnukes option?
Deitchman:   I can’t remember.
Hayes:   Do you know the month/date of the McNamara JASON debrief?
Deitchman:   The article in Science, vol. 179, Feb.2, 1973, pp. 459ff, which is about JASON, says that the meeting at Zacharias’ Cape Cod house was September 6th. Then, the McNamara debrief would have been around September 1st.
Hayes:   What do you think of Harold Brown’s reply (February, 24 2003, e-mail) to my question whether he had any knowledge of the JASON report and related briefings which states: “I do not recall being briefed on any such report and am sure that I would remember it if I had been. Separately, I find myself in agreement with what the excerpts say and believe I would have been in agreement at the time.”
Deitchman:   Re Harold Brown’s answer, I think that just about that time, Johnny Foster had replaced Harold as DDR&E (because he — Johnny — started to twist my arm about taking over Project Agile in ARPA during the last day or so of the summer study, out in Santa Barbara). So, if DDR&E was in on the JASON debrief of McNamara, it would have been Johnny who sat in.
Hayes:   Hal Lewis, the chair of JASON at the time of the nuclear weapons study says (telephone interview, February 25, 2003) said that the nuclear study that year was no big deal, but the “N” word got more play than it deserved; and that the debriefing with McNamara was just a lunch, not a formal briefing, and was to discuss what to do about the barrier. He also said to defer to your memory.
Deitchman:   Hal Lewis’ memory is probably much better than mine, but I do have a distinct memory of sitting around in a circle with McNamara and the others, and his bringing out the report and saying, “I’ve read it, and I don’t need a briefing [that alone was enough to make a lasting impression, after I had spent 2 years in the Pentagon and saw the short shrift many reports got], but let me ask a few questions.” Whereupon, he did. So it ended up being just a conversation, in which I also remember his remarks about the frustrations of the tactical air performance over Hanoi, and his expression of consequent interest in the barrier idea. That was what I call the debriefing. I don’t remember lunch, but Hal may have been at another session where there was lunch. Well, as I said at the outset, memory is a slippery thing.
Hayes:   The Pentagon outbrief would have been a third briefing session (JASON summer session report to itself, brief to McNamara, and then this one at the Pentagon)? What month/date did it take place?
Deitchman:   The sequence was: JASON briefed itself on last day of the study. Briefing to McNaughton, week or so later. Briefing to McNamara week or so after that. That takes us from mid-August into early September.
Hayes:   Finally, in your concluding comment, you suggest that further talk of nuke options halted as of Fall 1966?
Deitchman:   As far as what I was hearing.
Hayes:   However, Richard Steadman told me that although he was not aware of the JASON tacnuke study or Mu Gia pass bombing options discussions, he was aware of informal talk, primarily from the military, of tacnuke options in relation to the dykes north of Hanoi as a way to escalate.
Deitchman:   Bombing the dikes, in any way, was often discussed, but never seriously undertaken, on humanitarian and political grounds. That would have killed thousands, if not millions of people, thru’ starvation if nothing else, and I don’t think, given the tenor of the times, it would have been seriously considered at cabinet and presidential level.
Hayes:   Steadman said that the dyke nuking idea never went forward to a formal discussion. But we also have the Khe Sanh tacnukes discussions and memoranda (for example, from JCS Wheeler to CINCPAC Sharp) of Feb 1/68 asking for his smartest young planners to look at tacnuke options for relieving the siege if it proved necessary. So I am not sure that one can say that all talk of nuclear options ended. Interestingly, one of the reasons that the tacnuke option was examined at Khe Sanh, according to the memoranda, was that if Khe Sanh had turned into a Dien Bien Phu, and such a study had not been done, then the Administration might have found itself open to criticism. Put another way, the existence of the capability generated a political imperative that its use be examined. Anyway, I would be interested in your reflection on these subsequent “nuclear balloons” that rose to the ceiling and were either punctured or simply deflated and went away.
Deitchman:   Actually, the personnel part of the “air supported anti-infiltration barrier” was deployed around Khe Sanh, and was very instrumental in ending the North Vietnamese siege. With the weight of conventional artillery and aerial bombardment that was brought to bear, nukes would have been redundant or superfluous. The Marine major who became the artillery officer at Khe Sanh had visited us in Santa Barbara, and we discussed with him the nature of the Ho Chi Minh trails, and also described the barrier scheme to him. When the sensors arrived on scene, he knew exactly how to use them to find the NVA positions and movements and bring fire on them. I was in part instrumental in their use at Khe Sanh, in that I carried messages about the use of the barrier from Sec. McNamara to Gen. Westmoreland on a post-study visit to Vietnam.
Seymour J. (Sy) Deitchman Biography
Private consultant on national security, research and development management, and systems evaluation

Deitchman, a mechanical and aeronautical engineer by training, served at the Institute for Defense Analyses (IDA) for over 28 years, and from 1982 through 1988 as Vice President for Programs with responsibility for planning and supervising the IDA research program and ensuring its quality and performance. In the Defense Department in the 1960s he established and exercised general oversight of the DOD program of R&D support for Southeast Asia operations, and then he managed such programs at the Advanced Research Projects Agency (ARPA). Before that he held several technical positions that included work on air traffic control and the early phases of army air mobile forces. His personal professional work has covered areas including air and ground transportation, tactical aviation, space systems and many aspects of air, land and naval warfare. He has been a member of various government and NATO advisory panels, notably in the current connection, the Strategic Defense Initiative Organization (SDIO) technical advisory panel during the 1980s. He is currently a member of the Naval Studies Board of the National Academies/National Research Council. He is the author of six books and numerous published papers on national security matters. Mr. Deitchman was working at IDA at the time the JASON report on tactical nuclear weapons in Vietnam was written in 1966, and is acknowledged in the report.