At risk were the technical designs of U.S. reentry vehicles that carry nuclear warheads such as the W-88. Previous disclosures in Congress revealed that Chinese spies and workers at Los Alamos National Laboratory was able to obtain data on the nuclear warheads themselves.

Wednesday's revelations indicate that China also was able to gain access to design information on how the reentry vehicles maneuver through the high upper atmosphere once separated from their launch vehicle missile carriers.

Such data is as classified and closely held as the weapon information itself, according to committee chair Sen. Richard C. Shelby (R-Ala.). Shelby said Wednesday that the leaked data was among the most damaging obtained by Chinese spies, working at Los Alamos during the mid-1990's.

The warheads and reentry vehicle technology concerns the weapons deployed aboard U.S. Trident submarines, and forms the basis of the Trident II sea-launched ICBM.

When coupled with reports that China also obtained ballistic missile technology from the U.S. and Russia, the package of data suggests that China was able to rapidly advance its missile and nuclear weapons programs, possibly for the design of a new mobile ICBM. But the same report released yesterday indicated that there has been no indication that China has in fact been able to use the data to develop either a new warhead or missile system. But it seems that such a development is only a matter of time, according to the intelligence report.