PARIS

The United States last week attacked European Commission proposals to label genetically modified foods saying they are contrary to free trade (see Nature 384, 502; 1997). Raising the prospect of a trade war, Dan Glickman, the US secretary for agriculture, said that America would “not tolerate” segregration of modified bulk products — such as maize — from their traditional counterparts, which he described as impracticable.

This hard line reflects that of the World Trade Organization (WTO), which has ruled that countries cannot refuse imports or require labelling unless they can either show that the product does not meet international standards or produce scientific evidence of risk (see Nature 384, 301; 1996). “Sound science must trump passion,” declared Glickman, who argued that genetically modified foods are safe.

The US position could, if not modified, make a trade war inevitable. The ‘mad cow’ crisis has made European consumers suspicious of scientific reassurances about safety. As a result, Europe is likely to face up to any US challenge at the WTO. Even if the United States won its case, it would probably face a backlash from consumers and retailers against US goods.

The commission adopted the labelling proposal as a directive last week, and it should become law in the European Union by the end of July.