It can't be called a show trial, though the proceedings against Stern Hu and three other Rio Tinto employees shared some features of the infamous Moscow trials of Joseph Stalin's rivals in the 1930s: murky, ad hoc rules, and confessions by the accused after memory-refreshing time in the cells.

The Shanghai trials were essentially closed. Foreign journalists were told the cavernous court building had no room for them, and local media told not to publish any coverage. The Australian consul general was allowed in for part of the trial, then kicked out for the part that was the most important for clarifying the operating environment for foreign businesses: what is a legally protected secret and what is not.

But it was an exemplary trial, and the stiff jail terms handed down by Judge Liu Xin, after retiring to deliberate this complex case for a whole five days, were a swingeing seven to 14 years. If, as the Hong Kong website Asia Sentinel comments, this was meant as ''a warning to foreign suppliers not to play commercial hardball with Beijing'' it certainly worked with Rio Tinto (though not with Google).

The mining giant's chief, Tom Albanese, was in Beijing cultivating circles of influence as his employees faced the music in Shanghai, having conceded a major stake in a new African iron ore mine to his pushy Chinese shareholder, the state-owned metals group Chinalco.

No sooner had the verdict and sentences came down than the Shanghai four were sacked and condemned by Rio Tinto for ''deplorable behaviour that is totally at odds with our strong ethical culture''. Rio Tinto had already got its in-house lawyer to conduct a review of its own behaviour in the alleged bribery and theft of commercial secrets, and declared itself unwitting and innocent.

The Chinese prosecutors did not go as far as hauling in Rio Tinto itself or any higher-echelon executives to face charges, even though it has been reported that there is evidence the stolen ''secret'' information was sent by the Shanghai team to others in Rio Tinto, presumably for the company's commercial benefit.

But why would they? Albanese has put this giant company in the abject position that Beijing seeks. It started with his ill-judged takeover of Alcan for $US38 billion in 2007, to ward off a feared takeover by BHP-Billiton, which led to Chinalco moving in on debt-laden Rio with China's foreign reserve mountain behind it. When this was blocked by Canberra's understandable wavering on foreign investment clearance, China's state agencies were unleashed to subdue the breakaway iron ore market.

The Shanghai four have provided a convenient way of ''killing the chicken to scare the monkeys'', as the Chinese saying goes.

A lot of public reaction in Australia sees the claimed lack of fire in Canberra's consular support of Stern Hu, the only Australian citizen among the four, as related to his ethnicity. Had he been a Caucasian with a familiar European name, fierce indignation would have swept the nation and steeled our politicians to much stronger protest.

This is unfair. Neither the Rudd nor Howard governments has stepped back from supporting Asian Australians in foreign court cases, including several involving the death penalty.

The racism and lack of courage is on the Chinese side. Beijing is reluctant to accept that anyone can voluntarily stop being Chinese and transfer full allegiance to another country. Rather than put a Westerner, Korean or Japanese from an upstart enterprise in the dock, they go after the local or ethnic Chinese staff, who may have relatives and assets in China to think about.

Judgments on this case have to be tentative, at least until Judge Liu's ruling is translated and published, and trials held for the Chinese counter-parties to the alleged bribery.

It appears that Hu and the others are accused of receiving rather than giving bribes, hence Rio Tinto's ignorance. The benefit they were able to confer in return was allocation of iron ore directly to smaller, privately owned steel mills outside the import channels licensed by the Commerce Ministry-run China Iron & Steel Association.

This official import system was itself an invitation to rent-seeking and corruption by the big state steel firms it included. It would not be surprising if the four Shanghai executives succumbed to the temptation of winning Rio Tinto some sales at high ''spot'' prices outside the system, and getting rewarded themselves in the process.

As one senior China analyst - unnamed because he visits China frequently - pointed out, Shanghai is a particularly corrupt environment. ''The former municipal party secretary is in jail for life, as is the former head of Sinopec, the largest petroleum retailer in China with its headquarters in Shanghai, because of corruption,'' he said. ''[President and party chief] Hu Jintao has not been there for 18 months because, among other things, he does not want to be tarnished by the corruption issue.''

The commercial secrets charge, however, seems much more spurious. The secrets appear to have been forecasts given at a conference held by the China Iron & Steel Association, hardly a venue designed for tight confidentiality, and a production plan by one big state steel producer. We don't know how these were obtained. But the point is, perhaps, that anything can be declared secret.

In advance of more definite information, Rio Tinto's rush to cut off the Shanghai four is unedifying. They have confessed to receiving payments - after months of close and oppressive confinement, with limited access to legal aid - but disputed that these were bribes. A guilty verdict is automatic in Chinese courts. Appeals could still be lodged, for what they are worth.

Rio Tinto has some history of mixing business and espionage. Information gathering by Hu and colleagues would have been part and parcel of their jobs, the results expected at head offices in Melbourne and London. The problem in China, again, is that secrets are what the government decides is secret at any moment - even analysis based on published data. But spare us the protests of total purity from this mining company.