The world commemorates International Holocaust Remembrance Day on Tuesday, January 27 – which also marks the 70th anniversary of the liberation of the Auschwitz concentration camp.

At Auschwitz, about 300 survivors of the concentration camp, along with thousands of others, will participate in a commemoration ceremony.

In Prague, a two-day conference that will include a ceremony at the site of a concentration camp at Terezin was organized by the European Jewish Congress.

While the atrocities of the Holocaust took place seven decades ago, the dangers of murderously violent anti-Semitism are hardly a thing of the past.

As recent events in France have tragically proven, hatred of Jews remains a force so powerful that the future vitality and continuity of Jewish communities throughout Europe has been questioned, even in places where levels of anti-Semitism are relatively low, such as Britain.

Murderous hatred of Jews has not gone away. But one important thing has changed: Jews no longer rely solely on the compassion and good graces of the world for their survival.

And this makes all the difference.

A combination of factors makes many parts of Europe highly inhospitable for Jews. Europe’s ongoing economic malaise, which has hit some countries (France, Spain, Italy, Greece, Ireland) worse than others (Germany), has historically led to the fostering of Jew hatred.

Skepticism regarding the European Union project has included a reassertion of strongly nationalistic elements which have singled out Jews, the ultimate outsiders, for special censure and as a foil for differentiating “us” from “them.”

A combination of immigration and high natural growth has resulted in the swift growth of Muslim communities throughout Europe. While the vast majority of these newcomers to Europe are law-abiding, nearly all of the murderous attacks against European Jews in recent years have been carried out by Muslim extremists.

European leaders have taken the threat against Jews seriously.

They realize that violence directed against Jews – particularly violence motivated by a fundamentalist, reactionary reading of Islam – represents an assault on the foundations of liberal democracies.

A number of countries – including France, Britain and Germany – have taken steps to track European Muslims who have traveled to Syria and Iraq to fight with Islamic State or other offshoots of al-Qaida. Legislation that enables European authorities to monitor the Internet and share intelligence is also being considered.

European countries have also beefed up security outside synagogues, Jewish community centers, schools and other conspicuously Jewish institutions.

There have also been calls for special legislation that would outlaw hate speech of all kinds, from xenophobia and anti-Semitism to homophobia and misogyny. Police and law enforcement would then be empowered to prosecute and even imprison those who spout hate speech.

But while the fight against anti-Semitism is noble and important, we can derive little but discouragement and a sense of futility from the thought that just 70 years after the most horrific genocide in history, we are witnessing in the very same place a return of this lethal obsession. If the lesson has not been learned by now, it never will be learned.

Transforming Jewish schools, synagogues, groceries and even whole neighborhoods into quasi-military zones ringed with police and soldiers might provide more security to Jews, but they also serve as humiliating reminders of the ineradicable nature of Jew hatred.

Similarly, irrational hatred of Jews cannot be legislated away. Indeed, the stifling of speech only pushes it underground.

Purveyors of hateful ideas are transformed into martyrs. The popularity of anti-Semitic comedian Dieudonne has probably increased since the French supreme court for administrative justice upheld a ban of his show in the city of Nantes. Legal action certainly has not stopped the man from expressing his despicable opinions. The reality is that large numbers of French citizens identify with Dieudonne’s humor.

Legislation will not change this sad fact.

Just 70 years after the Holocaust, we are confronted with a stark reality: anti-Semitism remains a danger. History’s lessons have not been learned. The situation of the Jews in Europe is once again precarious.

But unlike 70 years ago, Europe’s Jews need not rely on the rectitude of their hosts. They have a choice.