It all began, disconcertingly for US intelligence, with what is known in spy circles as a "walk-in."
One day in 1995, a Chinese national approached the CIA with a stack of official papers from China. To their shock, the agents found one document classified "secret" that contained design information on seven US nuclear warheads including the W-88 - the most advanced in the American arsenal.
Worse, the agency later concluded, the unsolicited "walk-in" had been directed by Chinese intelligence, for motives that are still debated, to advertise Beijing's possession of the US secrets.
The stunning loss of vital nuclear data, which spurred a governmentwide investigation, is the most damaging security breach revealed in a congressional report on China's efforts to obtain US military technology.
The bipartisan report, released yesterday, is likely to fuel even greater debate over China's long-term military intentions - and strengthen opponents of President Clinton's policy of forming a "constructive strategic partnership" with Beijing.
"It would be evidence of extraordinary near-sightedness to overlook the fact that the PLA [People's Liberation Army] is not a suitable military ally," says Rep. Christopher Cox (R) of California, chairman of the House committee that prepared the report.
While it condemns a lethargic government response to the spying, the report levels no major charges of wrongdoing at the Clinton administration.
Still, its 700 pages paint a vivid picture of a relentless, decades-long campaign by China to gather US weapons know-how bit by bit - relying on a vast "mosaic" of individuals, ranging from Chinese-American scientists loyal to the "motherland" to US business executives hungry for a share of the China market.
"The PRC's appetite for information and technology appears to be insatiable, and the energy devoted to the task enormous," the report says. In addition to nuclear warheads, China has gained key knowledge of US missiles and rockets, satellites, computers, and the neutron bomb.
Meanwhile, the report portrays US counterintelligence as little better than bumbling, with only "minimum security" at national energy labs and lax controls at satellite launchings in China, for example. As a result of bad communication, the president was not briefed on the spy losses discovered in 1995 until 1998, it says, nor was Congress informed in a timely fashion.
Traditional US counterintelligence techniques used against the former Soviet Union have proven woefully inadequate against China, stresses the report, asserting that Chinese thefts "almost certainly continue."
CHINA is likely using the data to develop a modern, mobile, multiple-warhead intercontinental ballistic missile (ICBM), creating in years - rather than decades - a far more potent threat to the United States than the 20-odd 1950s-era nuclear missiles Beijing now targets on US cities. Advanced ICBMs and shorter-range missiles could be deployed as early as 2002, the report concludes, posing a "credible direct threat" to the United States, Taiwan, and other Asian allies. Such a Chinese force could alter the balance of power in Asia.
"No other country has been so successful in stealing so much," Mr. Cox said in a Monitor interview. "No other country has the PRC's record of proliferation combined with the opportunity to spread the world's most successful weapons."
The report comes at a low point in US-China relations marked by mistrust over Chinese spying, trade frictions, and human rights abuses, as well as Chinese outrage over the NATO bombing of their embassy in Belgrade.
Also uncertain is how the public, already wary of China, will react. Completed in January, the report, perhaps the most comprehensive look ever at Chinese espionage in the US, was released only after months of negotiation with the Clinton administration over what could be declassified.
Perhaps the most damaging spying has involved China's illegal acquisition of US ballistic-missile technology and nuclear warheads. This began in the 1950s and continues "aggressively" today, often with the involvement of ethnic Chinese scientists, the report states.
China targets US scientists, especially ethnic Chinese, in several ways, including "arranging visits to ancestral homes and relatives; paying for trips and travel in the PRC; ... and doggedly peppering US scientists with technical questions by experts, sometimes after a banquet at which substantial amounts of alcohol have been consumed," the report states.
In the early 1950s, a Chinese scientist named Qian Xuesen, who had developed an expertise in jet propulsion during studies at the California Institute of Technology in Pasadena, was hired by the US Army and eventually worked on the Titan ballistic missile. Accused of spying, Mr. Qian lost his security clearance and returned to China in 1955 to become the "father" of China's nascent ballistic-missile program.
From the 1970s to the 1990s, a naturalized US citizen from Taiwan named Peter Lee worked at two national energy labs. After years of investigation, in 1997 the FBI charged Mr. Lee with providing China with classified data on techniques for creating miniature nuclear fusion explosions. He pleaded guilty in December 1997 to willfully passing on US defense information and served a year in a halfway house.
In 1995, following the CIA's receipt of the "walk-in" document and as China conducted a series of advanced nuclear-weapons tests, the US government began investigating Chinese theft of nuclear-weapons designs. A cross-referencing of personnel who worked on the W-88 warhead design and had contacts with PRC scientists produced a suspect, later identified by the government, named Wen Ho Lee, the report said. Mr. Lee continued to work at the Los Alamos laboratory until December 1998. He denies wrongdoing and hasn't been charged, although an investigation into his activities continues.
The stolen design information on the most advanced US nuclear weapons are likely to be emulated by the PRC in its next generation of ICMBs, the report states. A new generation of as many as 100 mobile and harder-to-detect "East Wind" ICBMs carrying "upwards of 1,000" nuclear warheads could be deployed by 2015, it says.