Developments in European science and science policy suggest that a new landscape is forming, one over which scientists can move as freely as they already do between Massachusetts and California.

The great scientific traditions of Europe have always had strong national identities. One thinks of Pasteur as French, Newton as British, Planck as German. But in moving towards an economically unified Europe, some national sovereignty had to be given up to serve a more communitarian vision. That same evolution is now taking place in science, as a powerful movement towards unified European research takes shape.

In a recent editorial in Le Monde, several Nobel Prize winners - including Francois Jacob, the French biologist, Bengt Samuelsson, the Swedish biochemist, Aaron Klug, the British biochemist, and Rita Levi Montalcini, the Italian developmental biologist - called for a restructuring of science policy that would double support for science, renew the focus on basic research and fund centres of excellence that would be regional and not national. Soon afterwards, the European Commission pointed out that European countries together produced proportionally more scientists then the US - but that scientists constituted a much smaller proportion of the working population. To help retain scientists, the Commission has advocated increased European Union investment in research and urged European co-operation to stop the "brain drain".

This growth of scientific collaboration in Europe is encouraged by the EU's sixth research framework programme, which provides grants to support work throughout the Union. The trend towards breaking down national borders should also be evident at a new pan-European event - EuroScience 2004 - taking place in Stockholm a year from now.

All this is good news but more work is needed in three areas. The priorities of a future European research entity should be restructured; governments both sides of the Atlantic should co-operate to plug any "brain drain" of talent away from Europe; and science policy needs to follow science along its cross-border course.

Some European scientists are reported to be dissatisfied with the balance of basic and applied research in the EU's framework programmes. They want more of the former and less of the latter. This dissatisfaction is fuelling discussion on the formation of a European research council, which might play a pan-European funding role like that of the National Science Foundation in the US. But if such a council is to develop, there needs to be a careful examination of the weight of different scientific fields in its research portfolio.

The US government should welcome these developments but it must also change its own position to assist the European science union. That means helping to tackle the problem of "brain drain", which received much attention in the 1960s but slipped out of view as European research expenditure increased and laboratories grew stronger. Many European commentators claim it has reappeared.

To slow it, US institutions need to ignore, at least for a time, the temptation to conduct overseas raids on scientists to fill permanent positions. An increased international scientific exchange will support, rather than inhibit, the equitable distribution of talent; and US science and immigration policies should be drawn in ways that ease movement of graduate and post-doctoral scientists in both directions. At the moment, the increasingly delicate visa situation - exacerbated by new interview requirements imposed by the US authorities - and the well publicised political differences between the US and Europe are impairing scientific exchange.

Last, the knowledge needed to construct a European science policy based on regions rather than nations must come from scientists themselves. Regional centres of excellence might provide a structure for policy discussion. But scientists still face the dilemma that while science is increasingly carried out across borders, science policy is still made by nations. The people best placed to construct a European science policy that brings together broad issues (such as the desirable balance between basic and applied projects) and narrower ones (such as stem cell research) are its leading scientists. It is a task worthy of their best efforts. The writer is editor-in-chief of Science, the international journal of the American Association for the Advancement of Science.

STANFORD, California - The Bush administration wisely backed away this month from formally challenging Europe's ban on genetically modified foods. It made no sense to antagonize Europeans over the food they eat when they are pivotal to more weighty matters, such as a new resolution on Iraq.

Still, Washington's threat that it would file a case against the European Union at the World Trade Organization had palpable benefits. Even the countries with the most hostile policies on engineered food - France and Germany among them - took steps toward allowing the European Union to work on replacing the blanket ban with a new system for tracing and labeling engineered food.

But the decision to back off also means that American farmers are still denied access to the lucrative European market. European consumers still pay more for food than they should. And developing countries that could most benefit from engineered crops are still frightened that losing their "engineering-free" status will make it impossible to export food to Europe.

Yet the science on food safety is as certain as it ever gets: There is no known danger from eating engineered food.

Having backed down, the Bush administration will find it hard to make the threat of going to the trade organization credible again and to continue the momentum toward removing Europe's ban. But even harder for the administration will be keeping domestic politics at bay.

The biggest threat to the success of the U.S. strategy on engineered foods is in the American heartland, which is angling for a fight with Europe over the ban as the 2004 elections approach. Senator Charles Grassley of Iowa called the decision to defer a trade dispute "the usual snobbery" of a State Department "more concerned about international sensitivities than the American farmer." Two tactics should guide the effort to open Europe's markets. One is to let the Europeans lead their own reform.

The engineered foods available to consumers today mainly benefit farmers who can grow them at lower cost. These foods look and taste the same as their traditional counterparts. For rich consumers in Europe willing to pay a bit more, it is easy to focus on hypothetical risks and shun these products. But the next generation of engineered foods, already nearing the marketplace, will have healthful benefits for consumers - fruits that contain cancer-fighting lycopene, for instance - and this will make it harder for European countries to bar all these foods.

During the furor last summer over Zambia's rejection of genetically modified corn, prominent European politicians were forced to declare that these foods were safe - a blatant contradiction of Europe's own policies.

The other tactic is outreach to the developing world. In the poorest nations, agriculture provides the livelihood of most of the population, and agricultural research proves that genetic engineering can make crops that poor farmers grow both healthier and more productive.

Yet research on engineered crops and support for farmers who grow them lack money, not only in U.S. agricultural development and extension programs but also at the international agricultural research centers that were the engine of the first green revolution. In the last decade American support for international agricultural research has declined considerably.

An American program that would finance agricultural research on novel uses for genetically modified crops in developing countries would help those countries and could eventually help open European markets.

An American-led effort to pry open those markets would backfire. But one led by a developing country could succeed, as Europe considers the moral issues posed by barring food from a country which needs to sell its crops to survive. So far, few developing countries (South Africa is one exception) allow commercial planting of engineered crops. The United States needs to overcome the fears of the developing nations by growing such crops there and demonstrating how they could transform agriculture.