Strasbourg's grand rabbi inspected graves desecrated with swastikas in a Jewish cemetery north of the French city on Dec. 14. (Vincent Kessler/Reuters)

Rabbi Andrew Baker is the American Jewish Committee’s director of international Jewish affairs and a special envoy on combating anti-Semitism for the Organization for Security and Cooperation in Europe.

Anti-Semitism is sometimes compared to a virus. While we can’t eliminate it, we at least know how to keep it under control. But what if we’re wrong? What if, like a virus, anti-Semitism has developed a new strain, unresponsive to all the traditional treatments?

The European Union’s Agency for Fundamental Rights' (FRA) new report on discrimination and hate crimes against Jews in the E.U. is deeply disturbing. Anti-Semitism is “pervasive” and "has become disturbingly normalized,” it says. “The persistence and prevalence of antisemitism hinder people’s ability to live openly Jewish lives.”

FRA polled more than 16,000 Jews in 12 E.U. countries this year. More than a third of those polled say they have considered emigrating. The first FRA survey, six years ago, surprised many, who imagined Jews were comfortable and secure in a prosperous and modern Europe. Instead, it revealed high levels of anxiety, Jews fearful of encountering anti-Semitic harassment or attacks, and 1 in 3 deciding not to wear any identifiable Jewish symbol in public.

Since then, international organizations and national leaders have issued declarations and virtually every European capital has hosted a conference on anti-Semitism. Yet, 85 percent of Europe’s Jews say anti-Semitism is a serious problem, and nearly 90 percent say it has worsened.

The three countries where Jewish pessimism has increased the most sharply are Germany (up 23 percent), Britain (up 27 percent) and Sweden (up 22 percent). If we are looking for newly effective treatments for the virus, these are good places to start.

A unified Germany opened its doors to thousands of Jews from the former Soviet Union. They and their children are part of a vibrant and visible Jewish community. But Germany also has a growing Muslim population, with 1 million new migrants from Middle Eastern countries. They account for the largest group responsible for anti-Semitic incidents, according to Jewish participants in the FRA report. Will migrants adopt Germany’s values of tolerance and responsibility for its past? Right-wing parties are also ascending. The new Alternative for Germany (AfD) party has shattered taboos and offered a space for anti-Semitism to return.

Six years ago, British Jews were among the most secure and confident in Europe. But it’s not physical threats that trouble them. The British Labour Party is now led by Jeremy Corbyn, whom most Jews consider anti-Semitic. His antagonistic view of Israel is a case study in how anti-Zionism can mask anti-Semitism. Once home to a majority of the country’s Jewish voters, the Labour Party is a hostile environment, and British Jews are facing the unthinkable — a possible prime minister ready to cross the line from anti-Israel animus to anti-Semitism.

Sweden’s reputation for tolerance was already eroding. The largest per capita share of the 2015 wave of Middle East migrants settled in Sweden. Most anti-Semitic incidents were also attributed to the Muslim population in the report. But right-wing parties that hold strongly anti-Semitic views are on the rise there, too.

Moreover, the Swedish government is among the most strident and outspoken critics of Israel within the E.U. As Jews are frequently conflated with Israel and held responsible for its perceived misdeeds, many think twice before voicing support for the state of Israel, knowing such support has consequences. When FRA asked Jews to identify the perpetrators of anti-Semitic incidents, they said about 30 percent come from extremist Muslims, 21 percent from the political far left and 13 percent from the far right.

Will Germany, Britain and Sweden find a way to reduce the numbers and reverse the trends? Can they provide answers for the rest of Europe?

Germany appointed a national commissioner to coordinate the fight against anti-Semitism. And it’s devoting millions of euros for programs to assimilate Muslim immigrants. Police are being trained to recognize anti-Semitic hate crimes. British Jews are finding allies to push back against the problematic shift in the Labour Party. The country has endorsed a definition of anti-Semitism with all of its examples, including those relating to Israel.

Sweden’s National Council for Crime Prevention is undertaking its first comprehensive analysis of anti-Semitism. If successful, it could finally force the government and Swedish society to face to the extent of the problem.

These countries illustrate European-wide challenges laid bare in the FRA survey, and the measures that must be taken to bring the anti-Semitic virus under control: acknowledge the sources of anti-Semitism even if it is politically incorrect; target educational programs to those most responsible; protect Jews and Jewish institutions; define anti-Semitism particularly as it relates to Israel; and continue to battle right-wing extremism.

It is a formidable challenge, and the very future of European Jewry will depend on its success.

Read more:

Jennifer Rubin: American anti-Semitism: It’s getting worse

Colbert I. King: Losing it after Pittsburgh

Robert J. Samuelson: Anti-Semitism and the broken promise of America

Jonathan A. Greenblatt: It’s time to call out campus anti-Semitism by both the left and the right

Dana Milbank: Trump’s America is not a safe place for Jews