The battle over agricultural biotechnology could reach a tipping point this week, when the World Trade Organization is expected to render its verdict on charges by the United States that Europe is illegally restricting imports of genetically modified crops.

Even if the United States wins, genetically modified foods would not flood Europe because citizens there remain wary of them. But the American government and the biotechnology industry hope a ruling in their favor would sound a warning to other nations not to follow Europe’s lead in restricting farm biotechnology.