What cost theft of US secrets?

Concerns are heightening over the potential magnitude of reported security breaches at America's nuclear weapons labs.

So far, it is not known for sure if China - or any other foreign country - did obtain computer data and codes that embody 50 years of US nuclear know-how.

But investigators have determined that these mathematical models, known as "legacy codes," had been transferred to an unsecured computer at Los Alamos National Laboratory in New Mexico, and that someone had accessed those files. The unsecured computer belonged to Los Alamos scientist Wen Ho Lee, now fired and under investigation for possibly spying for China.

If China did acquire the United States's nuclear legacy codes - and analysts are quick to note that this is still not certain - the implications for US and global security could be devastating.

Not only could US security be threatened by China, but also by countries that China may be helping, such as Pakistan, Iran, and North Korea. Regional power balances in East Asia, South Asia, and the Middle East could shift dramatically.

If the Chinese got these codes, "this has to be considered one of the two or three great intelligence coups of the 20th century," says Dan Gour, deputy director of political military studies at the Center for Strategic and International Studies in Washington.

These legacy codes are not simply "the how-to manual on the Internet for building a pipe bomb," Mr. Gour says. "This gives them the keys to the kingdom."

"These codes embody a lot of knowledge gleaned from testing," says Matthew McKinzie, a nuclear-weapons expert at the Natural Resources Defense Council in Washington. "The US has conducted over 1,000 tests; the Chinese have only conducted 45. There's knowledge there. The US weapons program is much larger in scale."

Even as the US Department of Energy, which runs the country's nuclear-weapons program, and the nuclear labs themselves scramble to handle criticism over reports of lax security, some government officials with knowledge of the weapons program are warning against overreacting.

Danger of exaggerating

It's an exaggeration to say that the Chinese can make no progress in their weapons program without stealing codes from the US, says one official, speaking on background.

"They had nuclear weapons that could reach us years before this espionage supposedly took place, and they'll have nuclear weapons that can reach the United States 10 years from now," says the official. "My strong impression ... is that it's important, but it's not the end of the world."

This official also suspects that some of the furor in Congress over Los Alamos may have some political basis - that the majority Republicans failed to "get" President Clinton over his affair with Monica Lewinsky and that they'll try to get him on nuclear espionage.

But yesterday, the uproar threatened only to get louder, as a report in The New York Times detailed a secret report to top Clinton administration officials last November warning of an "acute intelligence threat" from China and describing breaches of security of US weapons labs.

The secret report, prepared by US counterintelligence officials and shared with Congress, raises questions about why the Clinton administration didn't act sooner to tighten security at the labs. Even though Mr. Lee has been under investigation for possible espionage for almost three years, his office computer was searched only in March. Energy Secretary Bill Richardson waited until April 2 to shut down the computer system at Los Alamos.

According to the report, China's most urgent interest in acquiring US nuclear secrets is for the maintenance of its nuclear weapons, or "stockpile stewardship." In recent years, stockpile stewardship has become the main mission at Los Alamos, which has the world's most powerful computer - a machine capable of conducting three-dimensional simulations of exploding warheads.

Potential to expand

But if the Chinese did in fact gain the US legacy codes, they now have the potential to expand both the quantity and quality of their nuclear arsenal. Before, they would have had to go through a series of tests to build their own knowledge base.

"Now, does that mean we are today under a massive new nuclear threat? No," says Gour, of CSIS. "Does it mean that the Chinese could, within much-reduced timelines and cost and effort, create such a threat to the United States? Yes."

Much, he adds, depends on China's motives.

"Maybe China is going to be a great partner and a Democratic country," he suggests. "If not, are we looking at the beginning of the next cold war? I don't think that's what we want."