It may not be 1941, but Hitler's dream of a "Jew-free Europe" is taking shape, and it's time for the world to take notice, say human rights advocates.

A "virulent, open, and increasingly violent anti-Semitism" is rearing its ugly head across the European continent, according to Dr. Katrina Lantos Swett, president and CEO of the Lantos Foundation for Human Rights and Justice and chair of the U.S. Commission on International Religious Freedom.

The matter is a deeply personal one for Swett – her father, Tom Lantos, was the only Holocaust survivor to serve in Congress.

Europe has long been seen as a haven for democracy and human rights, but that face is changing rapidly for Jews there, many of whom question if their children will even be able to live there.

"Jews are being physically threatened. Their institutions are being physically attacked. They are being killed because they're Jews," Swett told CNA. "And the only reason many, many more haven't been killed is because of security measures."

Describing her recent solidarity visit to France's Jewish communities, she noted that many parents "don't see a Jewish future" for their children in Europe. Emigration from the continent is rising and will likely continue, with popular destinations being Israel, the United States, and Canada.

Just how dramatic will the shift in immigration numbers and demographics be? That remains to be seen.

Anti-Semitism has a centuries-old tradition on the continent, but it went underground after World War II, and for decades Jews lived there peacefully, Swett stated.

"You now have things that would have been almost inconceivable," she said, referencing "thousands of people marching down boulevards in main streets of major European capitals with signs saying 'Hitler was right'," as well as vandalism and destruction of Jewish synagogues and businesses.

The attacks have gotten so bad that the French government is providing security for Jewish schools, synagogues, and community centers. Earlier this year, 10,000 military personnel were deployed to protect potentially sensitive locations.

The Jewish community is generally thankful for what they view as a "sincere" action on the part of the government, she added, but "no one believes that that sort of incredibly forceful response is sustainable ad infinitem." The community already asking the question of what happens once the security leaves.

In some cases, Jews also risk their personal safety walking around major French cities while wearing public displays of their religion. "This is a pretty disturbing and chilling development, the notion that people have to sort of hide their identity in order to be safe in their own country," Swett stated.

Many of these attacks are coming from immigrant Muslim communities, who have not assimilated or been accepted into society and are "themselves the victims of discrimination," she said.

Meanwhile, while the French government may be actively protecting Jews, political parties in other countries are openly hostile and anti-Semitic. In Hungary and Greece in particular, far-right parties with an anti-Semitic agenda have gained a political foothold.

"You find in both virulently anti-Semitic rhetoric being spouted by their members and their leaders," said Tad Stahnke of the organization Human Rights First.

Stahnke has authored a report on anti-Semite politics in the two countries, "We're Not Nazis, But…" He explained to CNA how the rise of such far-right parties is a recent and troubling phenomenon, and that "anti-Semitic rhetoric has become a part of the political mainstream."

The Jobbik party is the second-biggest "political force" in Hungary, Stahnke said. He recorded in his report instances of party officials promoting bigotry, authoritarianism, and Holocaust denial, adding that some have already "told Jews to start looking for a place to hide."

According to one recent report, a Jobbik member of parliament spat on a Holocaust memorial in Budapest.

Meanwhile, Greece's Golden Dawn party is openly violent and has deep Nazi roots. It won 10 percent of the vote in European Parliament elections in Greece last May – the third most out of all the parties. It won about 6-7 percent in national elections in January.

"Most of their leadership is under indictment, so they seem to be a stubbornly resistant force in Greek politics, despite the fact that there's a major criminal case being brought against them for engaging in violent activity, mostly targeting dark-skinned migrants in Greece," Stahnke explained.

The party indeed has a Nazi "background," "orientation," and "ideology," he insisted.

In some cases, Europe's Jews are also publicly being pressured to criticize the state of Israel – something they are extremely reticent to do even if they may disagree with the country's policies.

"With a growing open hostility towards the state of Israel, many Jews also find themselves in the extremely awkward position of sort of only being able to pass muster as a 'good Jew' if they are themselves openly hostile or highly critical of Israel," Swett said, a country they "respect" and "feel certainly a degree of affinity" for, whatever their own political beliefs may be.

The U.S. can help with European anti-Semitism, she said, but "we have to confront the dangers in a very clear-eyed way."

This would include "encouraging inter-faith dialogue," and especially empowering Muslims to speak out against all religious violence, she explained. In addition, positive stories must be circulated, such as the group of Norwegian Muslims who stood together outside a synagogue to protect it in a show of solidarity.

In addition, the U.S. and other governments must be more aware of anti-Semitic terror threats and "act pre-emptively" when a threat is predicted, she continued. For instance, with the individuals who attacked the Charlie Hebdo Paris bureau, "the French government knew these guys were trouble" and yet "they weren't being closely watched."

The question right now is ultimately not if Europe's Jews will leave the continent, but how many and how soon. They do not want to leave, but soon may not have a choice.

"This is not a community that wants to leave a country they love, a country that they have felt themselves to be very much a part of," Swett said of France's Jews.

"But they also are not kidding themselves and are not prepared to be in any way naïve about the circumstances they face."