A Sweeping History of Spying
The main stumbling blocks to releasing the report, Cox said, had been agreeing with intelligence agencies on what sensitive material should be redacted from the report. When asked when the report would be made public, Cox held his thumb and index finger an inch apart, saying “We are this close.”
     Cox said he did not believe that the current tensions with China, following the accidental bombing of the Chinese embassy in Belgrade, should prevent Congress from releasing the report.
     “Facts are not inflammatory, facts are facts,” he said. 
     Officials who have seen the Cox report say it provides a sweeping history of China’s efforts to obtain classified U.S. technology from the late 1970s through the 1990s.
     “The headline will be that the extent of Chinese nuclear theft is much broader than has been previously revealed,” said one official, who like others demanded anonymity. “The report asserts that the Chinese have acquired sensitive design information on virtually the entire current U.S. nuclear arsenal.”
     While much of China’s gains of U.S. nuclear secrets were in the 1980s when Republicans controlled the White House, the report cites evidence that Beijing gained U.S. neutron bomb technology as early as the 1970s and continued aggressive spying throughout this decade.
     President Clinton has acknowledged that security at the Energy Department nuclear weapons labs remained lax well into his watch. He began ordering extensive steps to improve security last year. 

Stolen Secrets
According to the officials, the Cox report discloses that the Chinese:
Acquired in the mid-1990s U.S. secrets about a high-tech weapon developed during the Star Wars missile defense program that uses electromagnetic waves to propel objects like missiles or shells. U.S intelligence ascertained that China had obtained the technology about the so-called rail gun, but they could not tell from where in the United States it was obtained.
Obtained some sensitive nuclear weapons information in 1995, according to an intelligence report that could not determine the source of the leak. An investigation is continuing.
Obtained in 1980 part of a missile guidance system called the accelerometer. U.S. intelligence ascertained that the Chinese did reverse engineering to develop their own version of the part. 

Espionage Wider Than Suspected
The Cox report discloses that U.S. intelligence indicates Beijing has obtained secrets about seven U.S. nuclear weapons, including the W-56, W-62, W-76, W-78 and W-87 nuclear warheads, the officials said.
     The W-87 warhead sits atop the MX Peacekeeper missile, one of America’s most sophisticated weapons. The W-62 and W-78 warheads are used on Minuteman III long-range missiles, another key component of the U.S. nuclear arsenal. The W-56 and W-88 warheads arm the submarine-based Trident missiles.
     Intelligence officials say the technology gains China made through spying enabled it to develop nuclear weapons similar to the United States, substantially updating an arsenal that just a few years ago trailed America’s by decades.
     While U.S. officials have raised significant alarm over China’s espionage and gains, experts caution that Beijing does not appear to have attempted mass production of nuclear weapons. It also keeps its weapons on a relatively low level of alert and does not appear to be trying to deploy multiple-warhead weapons that would escalate a nuclear arms race.
     The Cox report “fleshes out the picture and gives us more pieces of the puzzle. And it is eye-opening in that respect, the extent of China’s spying,” said Charles Ferguson, a former Navy officer and Los Alamos weapons lab scientist who is now an analyst for the Federation of American Scientists. 

China Arsenal Still Limited
But Ferguson noted that China has only 18 long-range missiles?all with single warheads that date back years in technology?while the United States has hundreds of missiles and more than 6,000 warheads.
     “The key is for the U.S. not to go into panic mode, and rather to think of ways to encourage stability and to encourage China not to go to multiple warheads,” Ferguson said.
     The government officials said most of the House committee’s conclusions come from a Chinese document dated 1988 and delivered to the CIA in 1995. It showed the Beijing government had gotten information about the yield, range and accuracy of each of the warheads.
     Much of the information about some of the missiles could have been obtained from open literature, the officials said, but other pieces had to come from classified U.S. materials. Authorities have not been able to pinpoint where the leaks occurred.
     U.S. intelligence was most alarmed about extensive detail in the Chinese document about the W-88 submarine warhead that could only have come from classified U.S. government sources, the officials said.
     The officials said the Cox report also discloses that U.S. intelligence detected that China tested “a series” of neutron bombs in the 1980s with the last detonation occurring in 1988. One official put the number at about six.
     At the time of the tests, China had not yet signed the nuclear test ban treaty. It eventually did so in 1996 but has yet to ratify the pact.
     During the Cold War, the neutron bomb was developed by the U.S. and China as a possible weapon against mass Soviet troops. It kills people with lethal doses of radiation without destroying buildings.

The Associated Press contributed to this report.