Review of more than 900 cables reveals campaign to break down resistance to GM products in Europe and other countries

American diplomats lobbied aggressively overseas to promote genetically modified (GM) food crops such as soy beans, an analysis of official cable traffic revealed on Tuesday.

The review of more than 900 diplomatic cables by the campaign group Food and Water Watch showed a carefully crafted campaign to break down resistance to GM products in Europe and other countries, and so help promote the bottom line of big American agricultural businesses.

The cables, which first surfaced with the Wikileaks disclosures two years ago, described a series of separate public relations strategies, unrolled at dozens of press junkets and biotech conferences, aimed at convincing scientists, media, industry, farmers, elected officials and others of the safety and benefits of GM products.

The report offers a further glimpse of the power of the agricultural and biotech industries in America, after the supreme court came down on the side of Monsanto in its effort to enforce its patented GM soybeans.

The court ruled on Monday that an Indiana farmer had to buy new seeds directly from Monsanto every time he planted the GM Roundup Ready soybeans.

The public relations effort unrolled by the State Department also ventured into legal terrain, according to the report. US officials stationed overseas opposed GM food labelling laws as well as rules blocking the import of GM foods.

The report notes that some of the lobbying effort had direct benefits. About 7% of the cables mentioned specific companies, and 6% mentioned Monsanto. "This corporate diplomacy was nearly twice as common as diplomatic efforts on food aid," the report said.

Wenonah Hauter, the executive director of Food and Water Watch, said it was unsettling to see the State Department investing so much effort into promoting industry. "I'm especially concerned to see how much of the cables have to do with changing laws and regulations of many of those countries," she said. "Instead of focusing on security and promoting democracy, they are focusing on pressuring foreign governments."

In some instances, there was little pretence at hiding that resort to pressure – at least within US government circles. In a 2007 cable, released during the earlier Wikileaks disclosures, Craig Stapleton, a friend and former business partner of George Bush, advised Washington to draw up a target list in Europe in response to a move by France to ban a variety of GM Monsanto corn.

"Country team Paris recommends that we calibrate a target retaliation list that causes some pain across the EU since this is a collective responsibility, but that also focuses in part on the worst culprits," Stapleton wrote at the time.

"The list should be measured rather than vicious and must be sustainable over the long term, since we should not expect an early victory. Moving to retaliation will make clear that the current path has real costs to EU interests and could help strengthen European pro-biotech voices," he wrote.