First, a little housekeeping, then onto the subject of Japanese nukes. In the comments section of my previous post on the Sankei article, I posted the full text in Japanese. Two readers have offered translations, which I think is a model use of the comment section. In that spirit, I am going to start posting the full text of various news articles relevant to posts in the comment section, rather than as text files.
I wanted to check into something that Jane noted—the strange persistence of the idea that Japan was merely “six months” away from a bomb.
It’s not, never has been, and—for all I know—never will be.
Japan’s Nuclear Capabilities
The Government of Japan has twice commissioned these kind of studies—once in 1968 and then again in 1995.
- In 1968, Japanese Prime Minister Eisaku Saito—acting through the Cabinet Information Research Office—commissioned for nongovernmental academics to examine the costs and benefits of an independent Japanese deterrent. Yuri Kase, who managed to acquire a copy of the document, provides the definitive account of the document in “The Costs and Benefits of Japan’s Nuclearization: An Insight into the 1968/70 Internal Report”, The Nonproliferation Review 8:2, Summer 2001, pp. 55-68. Kase, unfortunately, focuses on the second portion of the article, rather than the first, which enumerated the contemporary technical and economic hurdles faced by Japan.
- The Japan Defense Agency commissioned a 1995 study entitled, A Report Concerning the Problems of the Proliferation of Weapons of Mass Destruction “because of growing concerns in neighboring nations that Japan was preparing to go nuclear in response to” North Korea’s nuclear program—although the document was presumably also linked to Tokyo’s decision to support indefinite extension of the NPT that year. (See ”’95 Study: Japan and Nukes Don’t Mix,” Asahi News Service, February 20, 2003, posted in the comments section, and Michael J. Green and Katsuhisa Furukawa, “New Ambitions, Old Obstacles: Japan and Its Search For an Arms Control Strategy,” Arms Control Today, July/August 2000, link.)
What is different about the September 2006 report—based entirely on the Sankei Shimbun article—is that seems to focus on how, without any discussion of the strategic costs.
That worries me, at least a little.
The estimate—$1.7-2.5 billion over 3-5 years—however, is reassuring and broadly consistent with other estimates.
The best technical discussion that I know is a chapter in a book by the Stimson Center. [Jeffrey W. Thompson and Benjamin L. Self, “Nuclear Energy, Space Launch Vehicles, and Advanced Technology: Japan’s Prospects for Nuclear Breakout,” in Japan’s Nuclear Option: Security, Politics, and Policy in the 21st Century, Benjamin L. Self and Jeffrey W. Thompson, editors (Washington, DC: Henry L. Stimson Center, December 2003) pp.148-176.] Although Thompson and Self don’t make cost or timeframe estimates, they conclude that Japan remains “far” from a nuclear weapons capability based on arguments very similar to those that appear in the Sankei story—in particular, the emphasis on eschewing use of plutonium produced in Japan’s light water reactors and the difficulties associated with developing a feasible delivery system.
Overall, I think the leak of the government report is an interesting illustration of why a potential proliferator might make longer estimates than we see in the popular press. It is easy, as a talking head, to claim that you just grab some reactor fuel and turn a couple of screws. But, as a government official advocating an expenditure of the billions and a significant change in security policy, you probably want to do the job right. That means serious fissile material and real attention to engineering a warhead and a missile that would work together.
It is precisely these kind of concerns—how far a latent or virtual nuclear power really is from a bomb—that quietly inform very different assessments of the threat posed by Iran’s nuclear program. I would also add that Japan’s emphasis on a graphite moderated heavy water reactor is precisely why the Iranian reactor at Arak freaks me out.
A second estimate of Japan’s nuclear capabilities, one that I would love to acquire, is cited in the chapter on Japan by Kurt Campbell and Tsuyoshi Sunohara in The Nuclear Tipping Point: Why States Reconsider Their Nuclear Choices. Here is the citation:
Japan: Technical Paths to a Nuclear Detterence Background: Questions and Answers (Arlington, VA: CENTRA Technology, December 2003).
I think it is interesting that the arguments in the estimate described by Sankei remain the same as those made in classified US intelligence estimates from the 1960s and 1970s. A 1967 National Intelligence Estimate predicted that it would take Japan 3-5 years and 500-600 million dollars (about 2.8-3.4 billion in current dollars) to develop a nuclear warhead for use on a ballistic missile. [Those estimates were also broadly consistent with the best unclassified analysis of the issues, John Endicott’s Japan’s Nuclear Option: Political, Technical and Strategic Factors (New York, NY: Preager, 1975).]
The bottom line is, and has been for some time, that Japan has made large investments in a civilian nuclear power industry, without developing the sort of expertise that would allow the quick assembly of a nuclear device, or the production of delivery vehicles. At least, not inside six months.
Right, So Where’d They Get the Six Months?
Given all this, one kind of wonders how the crazy “6 month” idea became so persistent. One sees these kind of assessments all the time in the literature:
- Andrew Mack observed that “Estimates of the time it would take Japan to produce nuclear weapons vary from a few months to a year …”
- Richard Tanter told reporter Tim Johnson that “Every country in the region knows [Japan] can produce a nuclear device, a rather sophisticated one, probably in six months.”
- Richard Halloran quoted a “Japanese strategic thinker” as saying that “Japan is N minus six months”—“meaning it would take only six months to build a nuclear device after a decision had been made.”
- Paul Leventhal told Geoff Brumfiel that Japan was little more than “a screwdriver away” from a nuclear weapon. “Most [countries] think it could get a bomb in a matter of weeks to months, if not days.”
- Ariel Levite claimed that Japanese policy has allowed “Japan to remain within a few months of acquiring nuclear weapons.”
I have tried to find the origin of the “six month” estimate—but to not much avail …
Levite is the only person to provide evidence for the estimate—a well known January 1994 story in the Sunday Times by Nick Rufford (posted in the comments), citing British Ministry of Defense report that claimed Japan had all the components necessary for a nuclear weapon:
JAPAN has acquired all the parts necessary for a nuclear weapon and may even have built a bomb which requires only plutonium for completion, according to a secret government report [from the Ministry of Defence to the Joint Intelligence Committee].
[snip]
The report, sent last month, reveals that Japan has key bomb-making components, including plutonium and electronic triggers, and has the expertise to ‘’go nuclear’’ very quickly.
One expert who has seen the report said: ‘’They (the Japanese) could have acquired all the expertise for imploding a weapon without breaking safeguards. All they would need to do is select adequate amounts of plutonium for the core.’’
Levite doesn’t really focus on the credibility of the claims, especially the issues of using spent reactor fuel and the question of a delivery vehicle—issues central to the 3-5 year estimate. Nor does the Sunday Times actually say “six months.”
A second hint is a claim that Japan is the claim that Jane mentioned—that Japan is within “183 days” of constructing a nuclear weapon (that is one half of 365, rounded up … or six months). This is variously attributed to a senior Japanese official, defense official or politician.
Zhu Minquan provides the first reference that I have seen to the 183 day claim—although Zhu cited an article called “Exposed by Japanese Mass Media, Japan Can Make Its Atomic Bombs with 183 days” that comes from this not very reputable site. Sadly, no link to the Japanese mass media in question.
A little lexis-nexis action reveals the second earliest reference—a 2002 Straits Times analysis describing remarks by Tang Zhongnan, president of China’s Institute of Japan Studies, who reportedly claimed that a Japanese magazine Diamond Weekly in 1995 quoted “a senior Japanese official” claiming that “Japan could produce a nuclear weapon within 183 days.”
Ehsan Ahrari also in September 2004 attributed the remark to “an unnamed Japanese politician” in a July 1995 issue of the Japanese magazine Hoseki Gem—which is also how the People’s Daily sourced the story a few months earlier (although it attributed the quote to “a senior Japanese government official).
The real prize, however, goes to Neil Weinberg, writing with Kiyoe Minamiin in the September 5, 2005 edition of Forbes magazine. Weinberg describes the claim as having occurred “recently,” leaving the impression he heard the remark:
When asked recently whether Japan could go nuclear and, if so, how long it would take, a defense official replied that such a move would be constitutional but that Japan has no intention of doing so. If it did, he added, it would take 183 days.
Sigh.
No one actually seems to have posted a copy of the original article where the claim was made or provided a full citation. I am willing to be that no one on this list has actually seen the Japanese magazine article. I am even beginning to wonder if it exists at all. (Or, if it is going to turn out to be totally disreputable). The only thing I can say is that the originators of the claim clearly seem to be in China.
Either way, the “six month” estimate seems to be much older than either the Sunday Times story or the “183 day” claim. The oldest mention of the “six month” idea that I can find is from 1986, when David Fairhall in The Gaurdian quoted a “local expert” as claiming that Japan had “the technical capacity to produce a nuclear bomb in six months”—although Fairhall was trying to make a rather less alarmist point about the Japanese “nuclear allergy.”
Having looked at the technical reasons that Japan is several years away from a deliverable nuclear warhead and the strange persistence of the “six month” idea—it is hard not to conclude that “six months” is a wonky equivalent of the Biblical Forty. “Six months” is a rough estimate—on par with “a screwdriver’s turn” as the Leventhal quote suggests—intended to make the wonk look smart and satisfy hungry journalists.
The only problem is, it ain’t true.
Here is the Sunday Times article
And here is the relevant portion of the Straits Times analysis.
As you can see, the author is basically quoting Tang Zhongnan, president of China’s Institute of Japan Studies.
Finally, the 1986 reference to “six months.” Can anyone find something older?
I would be remiss if I didn’t make clear that the author was attempting to place Japan’s military power in context, not exaggerate it.
I have just searched Nikkei Telecom21, which is a very mild Japanese language form of Lexis/Nexis offered by the Nihon Keizai Shimbun. After searching all major newspapers, television news transcripts and Nikkei-related magazines:
1) I found no citations linking the terms “183 days” and “nuclear weapons”
2) The first citation where both “6 months” and “nuclear weapons” appear in the context of Japan being capable of producing nuclear weapons in six months’s time is in an Asahi Shimbun article of June 27, 1995 entitled: “Toward the Elimination of Nuclear Arms, Chapter 3.5 -The N-Minus 6 Months Countries” [N mainusu rokkagetsu no kuni (Kakuheiki kaizetsu e no michi dai 3 bu: 5)]
According to the article, an American study is the documentary source of the concept of Japan being only 6 months away from being a nuclear weapons state. The article states that in 1994 the Japanese Embassy in Washington sent the Ministry in Tokyo a copy of “Critical Mass: The Dangerous Race for Superweapons in a Fragmenting World,” by William E. Burrows and Robert Windrem (February, 1994). Inside that book (Does anyone have access to a copy? We are sort of already shut down for New Years here)the authors cite an anonymous Japanese person as the source for the 6 months figure.
I have a nagging suspicion that David Fairhall’s 1986 “local expert” was a former Ministry of Foreign Affairs or Defense Agency bureaucrat who possessed little actual knowledge of the technical aspects of nuclear weapon development—and that that individual’s half-baked assessment thereafter became canonical.
Oh, I have a copy of Critical Mass.
The book is a journalistic account that is often cited, but also quite unreliable. It was a real contribution at the time, but should not be treated as a primary source.
Burrows is also the author of the excellent Deep Black: Space Espionage and National Security (1987).
Oh, and good to have you blogging with us, Robot Economist.
The first time I ever heard the “nukes in six months” meme, it was in reference to Deborah Shapely’s “Nuclear Weapons History: Japan’s Wartime Bomb Projects Revealed” from the journal Science (Vol. 199, No. 4325. Jan. 13, 1978, pp. 152-157). A professor mentioned that according to the article, Japan was six months away from building a nuclear weapon at the end of World War II.
I looked into it and apparently that was a misinterpertation. The article says that when the Imperial Cabinet questioned Yoshio Nishina, the father of Japan’s Imperial-era nuclear weapons program, about how quickly he could make a weapon, he replied “six months.”
I’ve also been exploring the meme from the Japanese side. CINC parroted the claim in its Thinking the Unthinkable: Japanese nuclear power and proliferation in East Asia but did not cite anything to support the claim (even among the endnotes).
Does anyone have a copy of the “Nuclear Tipping Point: Why States Reconsider Their Nuclear Choices” edited by Mitch Reiss? There is an article in it on Japan’s nuclear recidivism by Kurt Campbell that may have some leads.
I checked The Nuclear Tipping Point (it is referenced in the post).
Campbell cites Levite and the Federation of American Scientists page.
Robot Economist –
Take care when you are typing out the later half of the URL to your new blog. “blogspot.com” goes to Blogger, while “blogspot.org” tends to plunk one down in a rather racier bit of cyberspace.
One last bit on the hypothetical Japanese nuclear arsenal: The NIE 4-66 available on the National Security Archive website (http://www.gwu.edu/~nsarchiv/NSAEBB/NSAEBB155/prolif-12.pdf) estimates it would take the Japanese two years to test a nuclear device.
Re: Burrows and Windrem, in Critical Mass, cite Richard Halloran (who I mention in the post) for the claim that “Japan is N minus six months” from the bomb.
The original Halloran source is his monograph, Chrysanthemum and Sword Revisited:. Is Japanese Militarism Resurgent? (Honolulu, Hawaii: East-West Center, 1991).
Harvard’s copy is in the Fung Library, which is closed until next week.
I recall that Henry Kissinger wrote an op-ed in the early 1990s where he also used the 6-month-to-a-bomb language for Japan. I can’t recall in which US paper this appeared but used to quote him on that. (I shan’t be looking for this op-ed as I am now in Colombia working with a human rights organization and am focused on other urgent matters.)
But whether it’s 6 months or 6 years Japan has the technical ability to build a bomb if it had the political will. We know it has the plutonium, including weapons-grade critical assemblies supplied by the US, so the questions which intrigue me and which seem far more relevant than any time-frame are: Does Japan now possess technical documents and/or plans on how to make a weapon, does any nuclear bomb research team exist and does it possess components or mock-ups of components from which a weapon could be made? I would like to hear the Japan government pledge to destory any such components or plans and affirm that no research team exists or existed.
Likewise, this leads to the questions of what happened to the technical documents and any bomb components that South Korea may have possessed during its bomb program. Do such documents and/or components still exist at the Daeduk research facility? Will S. Korea provide public proof that all weapons information has been destroyed?
By asking the above questions a fatal flaw in the NPT is revealed. The treaty does not prevent any country from nuclear weapons research or from holding nuclear bomb plans locked away in a dark safe somewhere. Or, for having unassembled componets for that matter.
And, about those hundreds of kilos of US-supplied weapons-grade plutonium in Japan (for nuclear reactor research purposes) – when will the US Department of Energy recover that material and put to rest the possibility if its diversion for weapons purposes? I’d say that could be done within 6 months, if the political will existed.
Perhaps I’m mistaken, but Tom Clements appears to be referring to HEU fuel assemblies, not plutonium. For background, see:
Global Cleanout: Reducing the Threat of HEU-Fueled Nuclear Terrorism, by Alexander Glaser and Frank N. von Hippel http://www.armscontrol.org/act/2006_01-02/JANFEB-heuFeature.asp
and
Reduced Enrichment for Research and Test Reactors (RERTR) Program at Argonne National Laboratoryhttp://www.rertr.anl.gov/
It has been 61 years, so far as I know, since any U.S. plutonium went to Japan.
One thing to keep in mind is that there are differing definitions of “nuclear weapon capability” that significantly affect timelines. Are we assuming a weapon deliberately designed to fit a current missile delivery system, a basic plutonium device, or any device that will produce a nuclear yield (such as a uranium gun weapon)? It seems to me debates about timelines are meaningless outside of such basic context.
Of course this also brings up questions of Japan’s strategic reasoning for weaponizing. It’s not inconceivable that Japan in a crisis would build and test whatever design it could complete the quickest (thereby demonstrating a weapons capability and nuclear deterrent) while working on a reliable, deliverable design that would take more time and resources.
Finally, from a more technical standpoint, Japan’s significant computer modeling capability could speed up the design process significantly from quoted estimates from the 1970’s and before. Who knows, perhaps Japan has already “tested” designs and only requires the materials and components to build them. Japan may already have some of the “tested” components built. Given the tensions with North Korea over the last decade plus, such preparations seem likely in my view.
The United States has been enjoying a “coherent” foreign policy from an obedient Japan. An interesting question to ask is how the United States will handle a nuclear-armed Japan, and prevent it becoming “independent” mind in its own foreign policy.
This is very interesting stuff; great job. One question though. It would be interesting to compare the time frame for the North to weaponise starting from where they are now and for these estimates for Japan. The 6 month thing always gave Tokyo some slack as to when to make a decision to develop an independent deterrent but could it be that the 3-5 year thing means that the crunch time for Japan to make decision about an independent deterrent is now or close to it? The fact that this study was comissioned is pretty interesting in itself.
To restate the obvious, the length of time it takes an entity to realize a project of which it is over-capable will depend strongly on the level of motivation.
Japan has technical and economic resource potentially available for a critical (e.g. existential) national project many times what would be needed to realize a bomb, a warhead (which might weigh a few tons if need be) and to adapt or modify an existing rocket or aircraft to deliver it, in a very short time.
The estimates that you are giving, of a few years, are based on the assumption of a normal bureaucratic process, perhaps with some political urgency for the party in power, but undertaken in a situation in which the decision may have been narrow and heavily opposed, with corresponding constraints on budget, sensitivity to possible mistakes or accidents, and the lack of total national commitment and fervor of those working on the project. Yes, under normal circumstances, or let’s say, if the political balance were to shift tomorrow just enough to barely support a decision to go nuclear, it would probably take Japan 3, 5 or more year years to field a deterrent. There might be a change of government and the project might be put on hold, or slowed. It might never be completed, the time might be forever.
On the other hand, if Japan were to take a turn back to militarism and then, when already very militarized, suddenly make the decision to go nuclear; or if “some catalyzing event” produced a national consensus that developing a nuclear deterrent was required and a sense of emergency requiring it in the shortest possible time, then, in such a situation, Japan could likely produce at least a crude nuclear weapon in as little as a few months, certainly well under a year. Such total commitment, a kind of worst-case scenario, is the unstated assumption behind “six months”, and you are fooling yourself if you think you can give a more precise estimate than that.
I would add that some few years and some few $bn in cost are the more interesting numbers for analysis of options the Japanese government might consider in response to less-than-catastrophic events such as the North Korean test or the general drift of things. The worst-case scenario is generally not the most likely or important one.
But “six months” is not some shibboleth that you can trace back in the literature. The various analysts you cite are probably making this estimate more or less independently. It is a realistic and accurate (to the feasible level of precision) estimate of the minimum time it would take Japan to produce some kind of nuclear weapon in an emergency situation.
Reminds me of a DOE estimate I saw years ago of how long it would take to produce X level of inventory under various scenarios… basically, they replied that they couldn’t light a bunsen burner in under 24 months, and it would take years to find any Plutonium, the way the closets were all packed with junk.
They were assuming the normal budget cycles, having to deal with environmental impact statements, congressional wrangling over whether to put the new facility in Alaska or West Virginia, etc – not “how fast could we build a bomb if the Chinese invasion fleet were sailing for Hawaii?”
On another tack, you do have to ask “What would Japan want to deter”? Any military attack on Japan by NK would most likely trigger a war that would end the state of NK’s existence. How much more deterred can you be? We needed nukes because fighting a conventional war with the USSR or China was never plausible. With NK it’s plausible, and thdere’s no doubt who would win, although the price in civilians casualties would be terrible. Would a nuke really help?
A previous poster said: “Perhaps I’m mistaken, but Tom Clements appears to be referring to HEU fuel assemblies, not plutonium.”
No, Tom is well aware of the difference between HEU and plutonium. He is most likely referring to the high-purity plutonium transferred by the US to Japan—circa early 1960s, if I’m recalling correctly—for incorporation into critical assemblies for research. I don’t recall the quantities, but they are not insignificant, and it is not reactor-grade Pu.
I’m sorry, Jeffrey, but your description of the Thompson and Self chapter’s conclusions is inaccurate. They do not conclude that there are “difficulties associated with developing a feasible delivery system,” as you say. Rather, they conclude that it is unlikely that Japan’s current space launch program is a cover for an existing nuclear delivery vehicle program.
Clearly developing a delivery vehicle would take time, but they do not address at all the issue of whether that time frame would be prohibitive or not. Their concluding comments regarding Japan’s ability to develop a ballistic missile delivery system are:
“It is certain that Japan could build a rocket suitable as a ballistic missile, should Japan desire to do so. Japan has had such strengths in rocketry for over thirty years. But, thecontention that Japan’s SLV program is a disguise for pursuit of a ballisticmissile capability is simply absurd.”
The same is true of the rest of their discussion, concerning plutonium: they make very few claims regarding the difficulty Japan would have (essentially their only point in that regard is that Japan’s Pu stockpile is in the form of reactor-grade Pu, which is usable but not optimal for a bomb), rather, their conclusions are that Japan is not CURRENTLY working on a breakout.
This does not invalidate your larger point, but it is an important distinction nonetheless.
Well, don’t apologize for disagreeing … but I think you are missing the point.
The question is whether developing a nuclear capable ballistic missile would take six months or three-to-five years.
I think Thompson and Self—although they do not place an estimate on the timeframe—are clearly in the camp that suggests three-to-five years.
I agree, of course, that Thompson and Self were discussing whether Japan was working on a breakout capability—but that seems to me essentially synonymous with the “six month” claim.
So, I don’t think it is inaccurate to describe the barriers to converting the H2 as “difficulties” associated with developing a feasible delivery system. At the same time, I can see that “difficulties” implies an ongoing effort. Perhaps I might have said: “The challenges associated with developing appropriate delivery vehicles.”
I agree with you that the important question is whether it would take six months or 3-5 years – I just don’t agree with you that there’s anything in the Thompson and Self chapter that really addresses that question directly. All they really give is a description of the current state of those resources which would need to be marshalled in order to build a bomb (lots of Pu, but sitting around in reactor-grade form; lotsa launch vehicles, but not optimized for warhead delivery) – and not even in very much technical detail, at all. If you are able to conclude from that description of the current state of affairs an estimate of how long it would take to get to a nuclear capability, that’s great (I mean that – no sarcasm) but I don’t see that their chapter by itself proves what you claim it does.
Well, I guess this is beating a dead horse, but I think the discussion on pp162-167 and pp171-176 certainly would support a crude timeframe and cost estimate—one that I admit in the post that they don’t make.
But sections do clearly enumerate the barriers that Japan might face (which would support a cost or timeframe estimate)> Self and Thompson make such an effort, for example, in the section on developing command and control arrangements, which concludes:
As Steve Dolley has indicated, I was earlier referring to Japan’s possession of US-origin weapons-grade plutonium, in the form of critical assemblies for nuclear power research. A DOE official told me last year that take-back of this material (hundreds of kilos, perhaps) had a low priority under the Gobal Threat Reduction Initiative (GTRI). Not sure if this would imply that DOE feels there is little risk of Japan diverting the material for weapons or if it’s being left in Japan for further research use (or, perhaps as a strategic stockpile…). In any event, it seems time to bring this material back to the US, possibly for vitrification along with other Pu under the reborn vitrification program at the Savannah River Site. (If you would like a copy of my December 2006 MOX/Plutonium update just e-mail me about that.) tomclements329@cs.com