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Regular Wonk readers will know that the question of how long it would take Japan to build the Bomb has been a subject of interest in the past. See here and here for starters.

Well, we now have a new low-ball estimate. Global Security Newswire (not exactly a scoop for ACW, I know) reports a speech from Gary Sick last week:

Experts have told him that Japan is so close to a weapons capacity that Tokyo “could do it, sort of, over a long weekend.”

I’d just love that word: “experts”…

Comment [21]

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We were discussing the origin of the widespread claim that Japan is “six months” from a bomb—and the earliest scholarly reference I could find was Richard Halloran’s Chrysanthemum and Sword Revisited: Is Japanese Militarism Resurgent. Halloran argues:

Japan also has the financial and technical resources to make nuclear weapons. A Japanese strategic thinker said years ago, and recently reaffirmed it, that “Japan is N minus six months.” He meant that Japan could build a nuclear weapon within six months of a political decision to do so.112

112. Conversations with the author in 1976, 1990 and 1991.

It is worth noting that the claim is made in passing; Halloran is making the point that Japan has the capability but not the desire to go nuclear. Whether it is six months or three years, doesn’t really matter to him.

It seems, though, that the “six month” idea dates to the mid-seventies—at a time when John Endicott’s careful study, Japan’s Nuclear Options, suggested a much longer timeframe.

I’ve been reluctant to speculate about why Sankei received this particular leak. Sankei is an extremely conservative paper, which I remember carrying some headline grabbing stories about extensive cooperation between DPRK and Iranian nuclear programs (I’ve posted two such stories in the comments).

Anyway, a reader familiar with Japanese media and its relationship with the Japanese government offers these thoughts:

With regards to the recent Sankei Shimbun article (and comments on the potential for Japan going nuclear) there’s one aspect to this story that should be mentioned.

The report, supposedly “leaked” to Sankei and citing the 3 – 5 year timeline for going nuclear, was most likely passed on to that newspaper by government officials deliberately.

Sankei is Japan’s most conservative publication, with strong ties to the ruling Liberal Democratic Party and the defense establishment. Although Sankei is the smallest national daily, the other papers are quite used to Sankei “scooping” them on these types of stories, since it’s an open secret that they have a direct line to the top levels of the government.

When the original Sankei article first came out, many of my colleagues and I interpreted this as a clever way for the Japanese government to send a subtle message to China. While publicly rejecting nukes, this is one way to say to China “the clock’s ticking” meaning that Beijing has to get serious about disarming North Korea, and fast.

China monitors virtually all Japanese news media, and even obscure articles are routinely translated into Chinese and often find their way into Chinese papers and websites. The Sankei article didn’t make a huge splash in the U.S., but it definitely raised eyebrows in China.

And PM Abe’s policy on this point is in contradiction. While publicly assuring China that Japan won’t go nuclear, he’s commissioning studies into the idea and encouraging public debate.

I am by no means an expert on proliferation, but I know how strongly Japanese citizens loathe North Korea. And the government has been taking a much stronger line than in the past (something the public has been urging for decades).

Should the six party talks fail and North Korea increases its arsenal, with China twiddling its thumbs, then I think it is highly likely that Japan will develop its own detterent, even if in secret a la Israel (although it’s unclear yet how they would work around the NPT).

But if they do it out in the open, then it won’t be too difficult to convince their public while NK is holding 10 or more weapons with delivery capability. China’s arguments against will be extremely weak, given NK’s history of terrorism and threats.

Comment [2]

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Just one thing to add to Jeffrey’s excellent post about Japan’s nuclear weapons potential…

According to a 1999 DIA primer on future threats (which can be found here), Germany and Japan “could develop a nuclear warhead within a year should the political decision be made to pursue such capability.”

[Cross-posted from TotalWonkerr]

Comment [6]

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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.

Comment [24]

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Here is the link to the Japanese language Sankei Shimbun story about a Japanese government study on developing nuclear weapons.

The story doesn’t have the document, but reproduces the “essence” in bullet points:

 一、小型核弾頭試作には最低でも3~5年、2000億~3000億円かかる

 一、核原料製造のためウラン濃縮工場拡張は非現実的。軽水炉使用済み燃料再処理をしても不可能

 一、黒鉛減速炉によるプルトニウム抽出が一番の近道

I gather (from a friendly translation) that this boils down to three points:

一 To trial manufacture a miniaturized nuclear warhead, the minimum time required is 3-5 years, and the cost is 200-300 billion yen.

一 To produce fissionable material, the expansion of uranium enrichment facilities is unrealistic; it is also impossible to reprocess spent fuel from light water reactors.

一 The extraction of plutonium from graphite-moderated reactor is the quickest route.

That’s not meant to be a literal translation and Japanese speaking readers are encourage to do better.

More later …

Robot Economist provides an “on the fly” translation in the comments section.

Comment [8]

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I’ve usually taken it as common wisdom that Japan, if it suddenly wanted to, could build a nuclear bomb in about 6 months. Articles and experts have quoted this figure.

However, there are reports quoting the Japanese newspaper Sankei of an internal Japanese report that puts the estimate closer to 3-5 years. The Japanese government denies the existance of this study:

The Japanese daily Sankei reported that experts at several government organizations concluded it would take at least three to five years to make a prototype weapon.

The experts also estimated that the project would cost about $1.68 billion to $2.52 billion and require the efforts of several hundred engineers, according to Sankei.

The experts did not say whether Japan should develop nuclear arms, the newspaper reported, only what such a project would require. The newspaper published a summary of the document, dated Sept 20 and titled “On the Possibility of Developing Nuclear Weapons Domestically.”

[Do any Japanese readers of ACW, or those with FBIS access, want to take a look for the original report and send us links or a translation if FBIS has it?]

I don’t know, this all sounds a bit odd to me. I am not sure where the 6 months claim originaly came from, and it does seem a bit fast now that I think about it. Maybe it comes from trying to put some numbers to as ‘little as a year’s time’ or maybe from a Septermber 2005 Forbes article which, as far as I can tell, first referenced a Japanese official saying that, it would take 183 days. (Exactly. On the dot. not 182 or 184…. what?!)

But 3-5 years? Why would it take a country with plenty of fissile material, reprocessing techonology, an advanced nuclear science establishment and a healthy economy, 5 years to build a prototype nuclear device? Some are worried that Iran could do it in 5, and they have nowhere close to the capablities and materials access of Japan. With a full industrial commitment, the US and Russia both did it in about 4 years starting from scratch. South Africa began working on a bomb design in 1971, with more intense work starting in 1974 and were ready for a “cold test” (without HEU) in 1977.

Two billion dollars is a lot of money, it is probably not something that would be a limiting factor if Japan wanted a bomb. Also, Japan gets about 35% of its electricity from 55 reactors. Would finding several hundred engineers be much of an effort? A few points of comparison: construction of the Rokkasho-mura reprocessing plant cost about 20 billion and employed 5,000 people.

ITAR-TASS says said that the difficulty in mobilizing the man power would be a moral issue rather than a techinical one: [I was emailed this article, so still looking for a link.]


The authors of the report said Japan possesses enough plutonium to manufacture thousands of warheads but such a project would have to mobilize several hundreds of engineers.

The latter will not be an easy task since the overwhelming majority of Japanese nuclear physicists are against turning their country into a nuclear power, an informed expert told Tass.

—Moscow ITAR-TASS in English 0148 GMT 25 Dec 06

Sure the physicists do not want to make weapons now, but that position is consistant with general public opinion in Japan. If public views were to shift – which would be a major change, but according to some experts, may be possible – I can imagine that the opinions of the scientific community would be just as likely to shift along with other Japanese citizens.

Comment [8]