Fairweather fixers of US war machine

The famous 1970s American cartoon "Chain of Command" showed a huge hand of Uncle Sam waving dollar bills in front of three men, kneeling, one behind the other. The first man is a fat general kissing the money, his backside being sniffed by a more attractive military man, whose backside is, in turn, being sniffed by a mortar-boarded academic. This image may have had in mind, at least partly, the Jasons, a group of scientists paid by the US Government to meet each summer to give secret advice on various topics, including strategy for the Vietnam War.

The idea of recruiting superstar scientists as summer consultants for the Government began in the 1950s, but the group did not formally exist until January 1, 1960. Several scientists were involved, but it is now widely agreed that the prime mover was Charles Townes, co-inventor of the laser. The origin of the name Jason is unclear, but it seems that the most plausible theory is that non-scientists in the US Government's sponsoring department, envious of the members' consultancy fees, coined the name as a reference to the Golden Fleece. If this is true, the implicit accusation of greed is unfair: the Jasons were paid poorly compared with most of the fat-cat advisers on Capitol Hill. The Jasons meeting this summer are being paid $900 (£490) a day.

Although the existence of the Jasons is widely known, the inside story is a well-kept secret. The American journalist Ann Finkbeiner has now written the first, and long-overdue, history of the organisation in this short, accessible book. Finkbeiner set herself quite a challenge because almost all of the Jasons' projects are top secret. She has examined the declassified documents and interviewed 36 of the 100 or so scientists who have been appointed to this scientific freemasonry, some of them talking to her on the condition that they remain anonymous. It seems that most of the Jasons signed up partly to make some extra money and partly out of patriotism. They all know that they do not have to work on projects that are not to their taste. Most of them seem to enjoy applying their skills to problems outside their usual fields of expertise in a think-tank environment. Most of all, they relish being part of a community of fine minds. Finkbeiner notes: "The words Jasons use most about other Jasons are 'remarkable' and 'refreshing'."

The success of the book largely depends on Finkbeiner's ability to get her hands on forbidden documents and to prise indiscretions out of her interviewees. Freeman Dyson, distinguished physicist at the Institute for Advanced Study in Princeton, gives Finkbeiner some of her best material, although he is careful not to give away any secrets. He is especially revealing about the Jasons' involvement in the Vietnam War. Dyson recalls that a former chairman of the Joint Chiefs of Staff close to President Lyndon Johnson remarked offhandedly that "it might be a good idea to throw in a nuke once in a while just to keep the other side guessing". Alarmed, Dyson decided to investigate the pros and cons of using low-yield nuclear weapons to destroy strategic targets in Vietnam. He worked with the leading physicist Steven Weinberg and two other Jasons, who concluded that the use of such weapons would be absurd. Dyson told Finkbeiner that they probably would not have issued a report if they had come to a different conclusion.

The Vietnam era was the Jasons' nadir, characterised by internal dissent, resignations and external accusations that some of them were "war criminals". Some were even publicly pilloried for their involvement, including the particle physicist Murray Gell-Mann, who was reportedly "bodily expelled" by officials during a lecture in Paris.

After Vietnam, the Jasons recovered strongly. One scientific success was in contributing to the invention of adaptive optics, whose techniques allow astronomers to increase the power of telescopes by correcting atmospheric distortion. This work, done in the early 1980s as a contribution to President Ronald Reagan's Strategic Defence Initiative, was top secret until the Government agreed to release it in 1991, after lobbying by the astrophysicist Claire Max, the first female Jason. Other astronomers were annoyed that this information had been needlessly kept secret; Dyson believes that "the secrecy held up progress in adaptive optics for ten years".

Secrecy prevents our knowing much about the Jasons' activities of the past decade. It does appear, however, that they had one of their most conspicuous successes in 1996, when their reports on the nuclear balance of power contributed to President Bill Clinton's decision to sign the Comprehensive Test Ban Treaty. It would be fascinating to know more about how their advice is evaluated behind the closed doors of government.

What is most surprising about the Jasons is that the organisation is unique to the US. Finkbeiner reveals however that the physicist John Wheeler and geophysicist Gordon MacDonald tried unsuccessfully to set up a British version of the group. She speculates implausibly that the main reason for this failure is that the best European scientists are more likely than their American counterparts to look down their noses at applied science.

But she implicitly raises a good question: why do more governments not make more use of their finest brains during the summer vacation?

Finkbeiner has written an intriguing book, although it is not lively enough to qualify as a popular text and too journalistic to be considered a serious historical study. Whoever writes the definitive account of this organisation will have to get much closer to its members, to the darkest recesses of the Government and the military, and do a lot more sniffing around.

Graham Farmelo is senior research fellow, Science Museum, London.