Last week, the United States' Justice Department indicted five individuals who are members of the Chinese People's Liberation Army. It claims they hacked into the computers of US companies to obtain trade secrets for the benefit of Chinese State-owned enterprises. China has refuted these charges.

According to a signed article in the Malaysian newspaper The Star, by accusing China of spying on specific US companies for the commercial benefit of Chinese enterprises, the US is trying to draw a very fine line.

The line the US is attempting to draw is between spying to benefit particular companies, which it regards as illegitimate, and spying to benefit the economy, which it seems to regard as legitimate.

Writing in the New York Times last week, David Sanger gave examples of foreign companies that have been targeted by US agencies. These include Huawei, a major Chinese Internet and communications company, China Telecom, one of the largest providers of mobile phone and Internet services in Chinese cities, and Pacnet, the Hong Kong-based operator of undersea fibre optic cables.

Nor is it just Chinese companies that are being targeted, the US has also spied on Petrobras, Brazil's national oil company, which has data on Brazil's offshore oil reserves and perhaps its plans for allocating exploration licenses to foreign companies, as well as Saudi Arabian, Mexican, and African oil companies.

The US National Security Agency has also spied on Joaquin Almunia, the antitrust commissioner of the European Commission, who brought charges against several US companies.

In each of these cases, US officials insist the US was not acting on behalf of specific US companies. But the US government does not deny it routinely spies to advance the US' economic advantage as part of national security.

This includes spying on European or Asian trade negotiators and using the results to help US trade. According to Sanger, when the US was negotiating in the 1990s to reach an accord with Japan, it bugged the Japanese negotiator's limousine, the main beneficiaries being US auto companies and parts suppliers.

The US is also widely believed to be using intelligence in support of trade negotiations underway with its European and Asian trading partners.

It seems for the US the fine line is fuzzy. And its spying is neither appreciated nor accepted by other countries.