The entire Chinese spy débâcle which has engulfed the United States this year rests largely on a piece of paper detailing aspects of a US nuclear warhead design purportedly stolen by China, which was delivered one day to an American embassy by a “walk-in” source who later turned out to be working for Chinese intelligence.

No one knows why China fed this highly sensitive material back to the United States in this way. Officials at the Los Alamos nuclear weapons laboratory have mischievously suggested that the real intent was to wreak havoc in the United States. They point out, only half in jest, that just such a tactic — the delivery of accurate intelligence to an enemy, followed by the revelation that the source of the intelligence was in fact a double agent — was identified by Chinese military historians in AD600 as a nifty means of sowing confusion in the enemy camp.

Whatever China was really up to, each twist and turn of the spying scandal — every piece of nonsense spoken about lax security at the laboratories and every clueless intervention from Washington politicians — has added a little credence to the still-implausible theory that the United States is falling victim to a fiendishly clever Chinese plot. In truth, it is difficult to imagine that any enemy action could have deliberately paralysed the US nuclear weapons complex as effectively as this domestically driven scandal has done.

The three weapons laboratories have been in turmoil for most of the year. Experienced laboratory staff, who have lived and breathed national security for much of their working lives, have been instructed to ‘stand down’ for days at a time, like errant schoolchildren, to listen to politicians' speeches or read security memoranda. The laboratories' extensive international connections have been thrown into chaos. Polygraph machines — a kind of embodiment of anti-science, feared by conscientious employees and scoffed at by professional spies such as Aldrich Ames, who passed dozens of polygraph tests — are arriving to keep tabs on some 5,000 laboratory employees.

A Senate proposal in response to the scandal, agreed to last week by Bill Richardson, the energy secretary, would place the weapons laboratories under a semi-autonomous agency within the energy department. But Vic Reis, who formerly ran the weapons laboratories as assistant energy secretary for defence programmes, already enjoyed considerable autonomy within the department. Richardson's decision to fire Reis — a widely respected research administrator with a strong technical background and good political connections — indicates that scapegoating has gained the upper hand over common sense. The energy secretary says that, if a new agency is established, its chief must have a “national security background”. He or she had better also have the leadership skills and technical credentials to win back the confidence of the laboratories' tormented employees.