The Chinese have called it their "Underground Great Wall" - a vast network of tunnels designed to hide their country's increasingly sophisticated missile and nuclear arsenal.
For the past three years, a small band of obsessively dedicated students at Georgetown University has called it something else: homework.Led by their hard-charging professor, Phillip A Karber, 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. In December 2009, just as the students began making progress, the Chinese military admitted for the first time that the Second Artillery had indeed been building a network of tunnels. According to a report by state-run CCTV, China had more than 3,000 miles of tunnels including deep underground bases that could withstand multiple nuclear attacks.
For decades, the focus has been on the two powers with the largest nuclear stockpiles by far - the United States, with 5,000 warheads available for deployment, and Russia, which has 8,000. The assumption for years has been that the Chinese arsenal is relatively small - anywhere from 80 to 400 warheads.
At the end of the tunnel study, Karber cautions that the same could happen with China. Based on the number of tunnels the Second Artillery is digging and its increasing deployment of missiles, he argues, China's nuclear warheads could number as many as 3,000.
This year, the Defense Department's annual report on China's military highlighted for the first time the Second Artillery's work on new tunnels, partly a result of Karber's report, according to some Pentagon officials.
For Karber, provoking such debate means that he and his small army of undergrads have succeeded. "I don't have the slightest idea how many nuclear weapons China really has," he said. "That's the problem with China - no one really knows except them."
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