Page 1 of 2 China tunnel and nuclear warhead follies
By Peter Lee
The recent hubbub over the size of China's nuclear warhead stockpile and its
underground maze of missile hidey-holes, the notorious "Underground Great Wall
of China" is, on one level, a battle between sensationalizing amateurs and
incensed arms control professionals.
On another level, it highlights a continuing nuclear security stand-off between
the United States and China.
The furor was kicked off by a November 29 article by the Washington Post's
William Wan. It described a study of China's strategic nuclear missile program
prepared by a team of students working under Phillip Karber, an adjunct
professor at Georgetown
University, in an arms control seminar. Wan's breathless opening set the tone:
Chinese have called it their "Underground Great Wall" - a vast network of
tunnels designed to hide their country's increasingly sophisticated missile and
For the past three years, a small band of obsessively dedicated students at
Georgetown has called it something else: homework.
Led by their hard-charging professor, a former top Pentagon official, they have
translated hundreds of documents, combed through satellite imagery, obtained
restricted Chinese military documents and waded through hundreds of gigabytes
of online data.
The result of their effort? The largest body of public knowledge about
thousands of miles of tunnels dug by the Second Artillery Corps, a secretive
branch of the Chinese military in charge of protecting and deploying its
ballistic missiles and nuclear warheads.
The study is yet to be released, but already it has sparked a congressional
hearing and been circulated among top officials in the Pentagon, including the
Air Force vice chief of staff.
Most of the attention has focused on the 363-page study's provocative
conclusion - that China's nuclear arsenal could be many times larger than the
well-established estimates of arms-control experts. 
coverage also provided an incendiary estimate:
Based on the number of
tunnels the Second Artillery is digging and its increasing deployment of
missiles, [Karber] argues, China's nuclear warheads could number as many as
The story as Wan presented it contained several
irresistible elements, to whit: 1) A team of renegade students displays 2)
ingenuity and elbow grease to 3) expose the errors of pointy-headed so-called
experts while 4) revealing Chinese perfidy and 5) alerting the people of
America to terrible threat.
This wonderful story had just two flaws: the parts of it that were true weren't
new, and the parts that were new appear not be true.
The true part of the story concerned that immense network of Fu Manchu-like
caverns, the "Underground Great Wall of China". Ever since Douglas MacArthur
threatened the People's Republic of China (PRC) with strategic nuclear bombing
during the Korean War in the early 1950s, the Chinese communists have been
industrious tunnelers, as tourists who have enjoyed Beijing's Underground City
- and the 500-meter airfield residing inside a hollowed-out mountain at the Air
Force Aviation Museum at Xiaotangshan outside the capital - can attest.
The existence of the strategic missile tunnels is also rather widely known,
although it seems to have escaped William Wan in his research for his article.
Wan incautiously wrote:
While the tunnels' existence was something of
an open secret among the handful of experts studying China's nuclear arms,
almost no papers or public reports on the structures existed.
one considers the tens of millions of readers of Xinhua and Global Times or the
millions who watch Rupert Murdoch's Phoenix Channel "a handful of experts",
Wan's statement is, regrettably, false.
In 2009, China's Second Artillery Corps opened their underground facilities to
journalists in order to publicize the investments the People's Liberation Army
(PLA) has made in improving the survivability of its nuclear arsenal and,
thereby, maintaining the credibility of the PRC's deterrent.
A Phoenix TV segment aired footage of tunnel construction and interviews with
PLA talking heads who proudly revealed that construction was now a matter of
mechanization and automation, not manual labor, banishing the Mao Zedong-era
paradigm of blue ants grubbing away at the naked rock with their bare hands.
Indeed, the new tunnels, with their automated blast doors and tiled surfaces,
evoke modern construction marvels like the Channel Tunnel. 
In December 2009, Xinhua ran a Global Times piece that careful invoked
extensive foreign reporting to reveal a massive project to harden China's
The story reported that, with the advent of more accurate missiles and more
powerful spy satellites by China's potential antagonists, the previous strategy
of hardening surface sites and mixing them with decoy sites was no longer
effective. Therefore, the government embarked on a massive, 10-year program to
put its entire nuclear deterrent deep underground, several hundred meters below
The program was first revealed on national television in 2006, apparently as a
riposte to claims by US analysts that China did not have a credible "second
strike" capability; ie the ability to launch a nuclear counterattack after
absorbing someone else's nuclear incoming.
With its usual subtlety, Global Times put the key money quote - the opinion of
a "Western expert" - in boldface:
If nuclear bunker-busting missiles
were employed against China's missile bases, it would take a strike of several
tens of missiles with yields of tens of megatons each striking at the same
point to penetrate; and it would take several more missiles to destroy the
The article let it be known that
the project might extend as far as 5,000 kilometers (just short of 3,000 miles)
and that it had been dubbed "the Underground Great Wall". The source: "foreign
That was the state of play in 2009: the tunnels were built, nicknamed,
displayed on television, and their length and other characteristics discussed
in the media; interested foreign spooks, analysts, and national security types
were well aware of the situation.
It is unclear what additional insight Karber's hardworking team at Georgetown
(which reportedly suffered from a dearth of Chinese-speaking members) actually
added to specialists' understanding of the tunnel project.
But it was the "3,000 warheads" claim, illustrated with what might go down in
arms control history as "The Karber Curve", that roused arms control analysts
to their greatest anger.
When asked by Asia Times Online if he had a comment on the issue, Dr Jeffrey
Lewis, an arms control authority and author of Minimum Means of Reprisal:
China's Search for Security in the Nuclear Age, responded:
yes, the claim that China has 3,000 nuclear weapons is utter bullshit.
China's holdings of weapons-grade nuclear material have been the subject of
intense interest and study. Open source and classified government studies
apparently agree that China has enough metal for about 400 warheads.
The best informed estimate in the public domain is laid out by Hui Zhang, who
lists the range of estimates in a recent paper for the Belfer Institute at
Harvard, concluding with his own figure for Chinese military plutonium stocks:
1.8 tons plus/minus 0.5 tons. The high end of the highest estimate is 4.35
plus/minus 2.2.5 tons 6.6 tons. A highly efficient warhead design would require
at least 5 kg of material. Per Zhang's midline estimate, that would yield 360
warheads; the highest range of the highest estimate would yield 1,300 warheads.
That is still a long way from Karber's 3,000.
The relatively stingy estimates of China's warhead stockpile is based on the
assumption that China's only two plutonium breeder reactors have been shut down
since the 1980s.
If Karber's team had discovered a new source of plutonium - or new evidence
that China's warhead stockpile had grown significantly beyond the estimates -
it would indeed have been a major find, and the arms control community would
have had considerable egg on its face.
However, it appears that Karber extrapolated his 2011 numbers from a 1995
estimate in a gossipy Hong Kong political magazine, Trend, which claimed that
China had a stockpile of 2,350 warheads.
After becoming aware of Karber's as yet unpublicized claims in September, China
arms control specialist Gregory Kulacki investigated the situation in Hong Kong
and drew the conclusion that Trend's number - which has circulated on the
Internet for years - perhaps itself grew out of 1986 estimates by a US naval
officer in a Western defense publication, not China's defense establishment.
The Trend magazine magazine estimate, by a pseudonymous author, filled with
enticing detail and the tantalizing statement, "According to information
revealed by China's Ministry of Defense on July 15 of this year, as of June 30,
1995, the Chinese Communist nuclear weapon stockpile held 2,350 warheads,"
remains unsourced and unconfirmed, leading a lonely existence as an extreme
outlier in estimates of Chinese warhead stockpiles. 
The Georgetown group was not even the first to unearth the Trend estimate; for
that matter, it did not even locate the original article. Karber's team leaned
on a short essay by a Singapore University graduate student, Yang Zheng, citing
the figure, and spin-off references on the Chinese Internet.
Yang's piece had already been ferociously debunked by Jeffrey Lewis in 2004 and
2009. Lewis ultimately determined that Yang also had not accessed the Trend
article himself; he had simply availed himself of a summary of the article
posted on a Usenet bulletin board by a curious mathematics professor.
This exhaustive sleuthing was missed or ignored by Karber, to Lewis'
considerable resentment, compounded by the fact that the Washington Post
declined to publish his letter, which Lewis subsequently posted on his blog. It
read, in part:
So where does Dr Karber get his wildly divergent
estimates? Nowhere does Mr Wan mention that Dr Karber's "analysis" of China's
plutonium production relies on a few Chinese blog posts that discuss a single,
anonymous 1995 Usenet post, subsequently plagiarized by a Singapore University
student, that is so wildly incompetent as to invite laughter. (I have mocked
this essay repeatedly on my own blog, Arms Control Wonk.com.) Actually, Dr
Karber doesn't mention this either. His research ended with the Chinese blog
posts, which is something that no responsible scholar would do. …
If I take any solace out of this pathetic episode, it is that Dr Karber's
students will have learned first-hand how not to do research. 
Karber's defense, as summarized in his appearance on al-Jazeera and an
interview with the New York Daily News apparently boils