Imagine for a moment that a researcher at a typical European or North American university was being threatened to halt his studies of, say, a new metal alloy for airplanes or a treatment for malaria. Is it likely that the university's leadership would respond by telling the researcher to abandon the work?

Of course not. Yet that's exactly what happened this spring at two German universities, where research into gene-spliced, or genetically modified (GM), plants has been halted following intimidation by antitechnology, anticapitalism activists.

In April, the rector and external advisory board of Nürtingen-Geislingen University in Baden-Württemberg "urgently recommended" that a faculty member terminate his field trials -- which had begun in 1996 -- on insect- and fungus-resistant GM corn. "We have always been very critical of this kind of research," said economist Werner Ziegler, the university's rector. "Lately things got out of control. There were email attacks, vandalism, intimidation and personal threats."

Also in April, the Justus Liebig University in Giessen, Hesse, announced that it was dropping plans for two small field trials of insect-resistant GM corn after protests by activists and local politicians. Both trials had been approved by the national consumer protection and food safety agency and were to be conducted on behalf of the national authority for agriculture variety and seed affairs.

"I am not happy at all with this decision," said Stefan Hormuth, the university president. "Unfortunately, we were no longer able to deal with the massive opposition from politicians and the general public. The university has a reputation in the region that we cannot risk losing."

Let's get this straight: German universities maintain their reputations by curtailing the academic freedom of their faculty and students in response to external demands and threats?

Gene-splicing has already yielded a panoply of useful agricultural products. These include grains and fruits that are disease- and drought-resistant, can grow with fewer chemicals, produce higher yields, and are more nutritious and environmentally friendly. Yet rather than welcoming the farming revolution that this technology could spark during the next decade, many countries have treated GM technology shabbily.

Alongside the recent censorship at the German universities, debilitating and even bizarre overregulation is the rule world-wide. Switzerland, which has banned the cultivation of any GM plants through at least 2010, even prohibits violations of the "dignity" of plants. In April, the Federal Ethics Committee on Nonhuman Biotechnology released a 21-page report that dithered nonsensically about what is ethical and moral to do to plants.

When research into gene-splicing isn't banned by universities or governments, radical activists often take matters into their own hands. In France, Germany and other countries, they have destroyed many small-scale field trials of GM plants, doing great damage to agricultural research, including critical risk-assessment studies. Several years ago, one German postdoctoral fellow was attacked with stones while trying to protect his virus-resistant sugar beets from vandals.

The latest incident of vandalism occurred earlier this month, when experimental wheat plants were destroyed at a research station near Zurich. The field trial was intended to assess the interactions of GM wheat with other plants, soil microorganisms and insects.

But Germany is the only country in which universities, normally refuges of free inquiry, have capitulated to the hoodlums. Such deplorable behavior is inexcusable in a Western democracy.

So far, British and American universities have refused to yield to similar threats and intimidation. When several faculty members at the University of California at Los Angeles became targets of animal-rights extremists, Chancellor Gene Block staunchly defended their academic freedom. Last year he condemned the flooding of the home of a researcher as a "deplorable and illegal act of extreme vandalism."

Government policies that unscientifically and inappropriately single out certain products or technologies as particularly dangerous only encourage activists. That's especially true if, as in the case of field trials of gene-splicing, they require informing the public about the location of test sites. Treating GM plants like other new varieties that don't require special warning signs or public announcements would be one step forward.

There is another obvious, related solution, one that has been consistently ignored by policy makers in both the European Union and Germany: Simply apply scientific and risk-based regulatory policies to the oversight of GM plants.

These policies have sufficed for less precise techniques for improving plants, such as hybridization, for decades. As the British scientific journal Nature editorialized in 1992, a broad scientific consensus holds that "the same physical and biological laws govern the response of organisms modified by modern molecular and cellular methods and those produced by classical methods...[Therefore] no conceptual distinction exists between genetic modification of plants and microorganisms by classical methods or by molecular techniques that modify DNA and transfer genes."

Putting it another way, government regulation of field research with plants should focus on the traits that may be related to risk -- the tendency to grow where one doesn't want the plant, toxicity and so forth -- rather than on whether one or another technique of genetic manipulation was used.

There are important lessons here. First, you shouldn't conciliate thugs by capitulating to them. Second, the problem would have been avoided entirely had public policy been crafted intelligently in the first place. And finally, when universities bow to intimidation and compromise academic freedom, they become part of the problem.

Dr. Miller, a physician and molecular biologist, is a fellow at Stanford University's Hoover Institution. His most recent book is "The Frankenfood Myth" (Praeger Publishers, 2004).