World War II and the destruction of European Jewry taught us that anti-Semitism not only kills Jews, but also poisons and ultimately destroys the society that harbors it. People of good will said, “Never again,” instituted courses on the Holocaust, and countered the image of the defenseless Jew by supporting the sovereign and democratic state of Israel.

Yet today, seven decades after the Nazi death camps became operational, that lesson seems to be already forgotten in much of Europe, where small and defenseless Jewish communities face a renewed surge of anti-Semitism. This Jew-hatred expresses itself in xenophobic politics; physical attacks and intimidation; and interference with basic elements of Jewish religious practice.

In some countries, openly anti-Semitic parties are growing alarmingly. Jobbik, the Movement for a Better Hungary, is the third largest party in the country. It calls itself a “radically patriotic party” that protects “Hungarian values and interests.” Openly anti-Jewish, it made news in August when its leader resigned after it leaked out that he had a Jewish grandmother.

Svoboda, a nationalist party that won 41 seats in the Ukrainian parliament in the November 4 elections, publicly praises the pro-Nazi Ukrainian Insurgent Army of World War II days and seeks to limit Jewish influence in the country.

And in Greece, the extreme nationalist Golden Dawn, which currently holds 18 parliamentary seats, has been rising in the public opinion polls. In September, 22 percent of Greeks viewed it positively, and in October, 14 percent said they would vote for it, which would make Golden Dawn the third largest party in the country. Its leaders deny the Holocaust and one has called Israel a “Zionist terror state.”

Elsewhere on the continent Jews have been assaulted on the street, often by young people of Arab extraction. In France, the number of anti-Semitic attacks during the first eight months of 2012 — including the cold-blooded murder of four Jews in Toulouse in March — was 45 percent higher than the comparable period the previous year. Although President Francois Hollande has pledged to protect the community, many French Jews live in fear.

Even in Scandinavia, with its tradition of tolerance, the minuscule Jewish communities face anti-Semitism. A recent survey found that “Jew” is the most common curse word in Oslo schools, and attacks and harassment in Malmo, Sweden’s third largest city, have triggered a Jewish exodus that has reduced the size of the community from 2,000 in 1990 to less than 700 today.

Ironically, while the physical threat to European Jews comes primarily from Muslim youths, the assault on Jewish religious practices emanates from circles that view both Jews and Muslims as alien elements. Circumcision and ritual slaughter of animals, central practices of Judaism that have analogues with Muslim rites, have come under attack.

Kosher slaughter is illegal in Sweden, Norway, Switzerland and Iceland. The Dutch Parliament passed a measure making it illegal in 2011, but was overruled by that country’s Senate. In January 2013, a European Union regulation will come into effect barring “unnecessary suffering” by animals during slaughter, a provision that will likely trigger new efforts in some of the 27 EU member-states against kosher slaughter.

The campaign against circumcision went public with a judicial decision in June, in Cologne, Germany, that the practice constitutes criminal bodily injury. While the decision was denounced by Prime Minister Angela Merkel and other German leaders, and in any case has no legally binding effect, it energized anti-circumcision activism in Europe. Many hospitals have suspended the procedure, and legislators in several countries announced plans to introduce legislation criminalizing it.

Since World War II, Europe has made great strides in creating more open and tolerant societies. This progress must be maintained and guarded with vigilance. If allowed to grow unchecked, anti-Semitic political parties, physical and verbal assaults on Jews, and restrictions on the Jewish religion will make Jewish life in Europe difficult, if not impossible, to maintain.

Brian Siegal is director of the American Jewish Committee’s Greater Miami and Broward Regional Office.