ON FEBRUARY 20, AN Austrian court sentenced the notorious British writer David Irving to three years in prison for denying in a 1989 speech that Auschwitz contained gas chambers. Many American observers had mixed reactions. They saw Irving as a loathsome anti-Semite but were uncomfortable with the thought of a person serving time behind bars for something he wrote or said, no matter how noxious. Journalist Michael Barone probably spoke for more than a few when he said that he "shuddered" at the news of Irving's imprisonment, "yet I can understand why Austria, like Germany, has laws that criminalize Holocaust denial and glorification of Nazism. History has its claims--heavy ones, in the cases of Germany and Austria." In other words, criminalizing speech might not be the American way of doing business, but it's understandably Austria and Germany's way of dealing with their unique Nazi past.

The trouble is that Austria's anti-Nazi legislation is the tip of an iceberg of political speech laws across Europe. Of course, all governments restrict some speech. But free expression is so foundational to democracy that there is usually a strong bias against restricting speech unless it poses a compelling and even imminent danger to others. The most pervasive and durable restrictions meet that test, applying to things like child pornography, false statements that result in demonstrable harm (defamation), the exposure of national security information, commercial fraud, and the proverbial shouting of "Fire!" in a crowded theater.

In addition, European countries have never had America's strong free-speech tradition. Nevertheless, three disturbing trends now underway in Europe together represent the greatest erosion of democratic practice in the world's advanced democracies since 1945. First, anti-Nazi laws are being adopted in places where neo-Nazism poses no serious threat. Second, speech laws have been dramatically expanded to sanction speech that "incites hatred" against groups based on their religion, race, ethnicity, or several other characteristics. Third, these incitement laws are being interpreted so loosely that they chill not just extremist views but mainstream ones too. The result is a serious distortion and impoverishment of political debate.

After 1945, Germany in particular passed strict anti-Nazi laws, making it illegal not only to form a neo-Nazi party but also to champion Nazi ideology, downplay Nazi crimes, print Mein Kampf, or even air the Nazi musical anthem, the "Horst Wessel" song. At the time, many believed that these restrictions met the test of averting immediate danger. Given what had happened between 1933 and 1945, it seemed airing pro-Nazi or anti-Semitic views was the equivalent of shouting "Fire!" in the crowded theater of Austria and Germany's troubled cultures. As it turned out, neo-Nazis proved too marginal even to come close to posing a serious danger to Germany or Austria's new democracies, with real neo-Nazis never winning even 5 percent of the vote. So the necessity for these restrictions became less and less clear with time.

But instead of being pared back, anti-Nazi legislation spread. Laws criminalizing Holocaust denial or minimization were adopted well into the 1990s in France, Switzerland, Belgium, Spain, and other European countries (and several countries outside Europe). What these laws could accomplish was unclear, since they were adopted when neo-Nazism's prospects seemed more remote than ever. In all these countries, including Germany and Austria, governments don't really have to ban neo-Nazis; voters do it for them through indifference. Nonetheless, anti-Nazi laws have proved uncontroversial, maybe because their sanctions fall on unsavory figures from Europe's anti-Semitic fever swamps.