NICE – I was getting out of our car, with my wife and children, on a main thoroughfare in Nice, when a young French Jewish woman walked over to us and, speaking in a heavily accented English, practically begged us to either get back in the car or at least take our yarmulkes off. “I don’t want you to get attacked. This is not a good neighborhood for Jews. Please get in your car and leave, or at least cover your kippa and put away your tzitzit.” She meant no harm. To the contrary, her panic was genuine.My 17-year-old son, Yosef, explained to her that neither was going to happen. “We’re not taking off our yarmulke. We can’t hide who we are.”We walked off, but we were spooked – not because we believed we were in danger, but because of her state of alarm. She was genuinely scared for us.And when my wife and I were buying tickets to a French museum, the woman who was actually selling us our tickets asked my wife to please put away her Magen David necklace. “I am Jewish, too. I also love Israel. But it’s not safe.”Welcome to France, the third-largest Jewish community on earth, a secret society of 600,000. By this I mean that French Jewry is vibrant, extremely well organized, passionate, and quite observant. There is one catch. You don’t know they are Jewish unless they reveal themselves to you.While walking in Saint-Tropez immediately after France won the World Cup and the entire city was reveling, a man on a scooter, with his girlfriend, started singing to us “Am Yisrael Hai” (The Jewish People Lives). He saw our kippot and outed himself.We saw the same thing happening while walking the streets of Cannes the day before. Many people whom we did not know were Jewish would say “Shabbat Shalom” or just “Shalom.” And I felt like our overt Jewish demeanor was bringing more people out of the woodwork.This does not mean, by any stretch, that French Jewry are doomed. To the contrary, I was amazed at their vibrancy, Jewish commitment and solidarity with Israel.On Shabbat morning I was rushing to the Chabad shul in Cannes, concerned that being a bit late would mean they would not have a minyan to pray. Imagine how surprised I was arriving and barely being able to even find a seat. The place was packed to the rafters, with hundreds of people in attendance, passionately praying, passionately Jewish – and this in a vacation destination where they could easily have skipped their communal obligations. I give credit to the excellent work of Rabbi Mendel Matusof and the other Chabad rabbis around Cannes for building Judaism on the French Riviera.Which brings us to this conclusion. For all the reports that we American and Israeli Jews read about growing French antisemitism, especially emanating from sectors of the Muslim community, and for all the reports of French Jews wanting to either make aliya or immigrate to Canada, French Jewry is still vibrant and thriving. What has changed is that it’s becoming more and more subterranean.Yes, you can still find large numbers of synagogues, kosher restaurants and Jewish community centers. What you don’t see in the streets, however, is Jews. Or you see them, but you don’t necessarily know they are Jews. Overt, identifiable symbols of Jewishness – like a kippa, Magen David, or tzitzit – are disappearing from French streets and cities.Why? Because French Jews are genuinely concerned about a possible attack.There is one glaring exception – Chabad rabbis and community members, who walk around with black hats, long black coats, tzitzit flying, and the Chabad women dressed in clearly identifiable Jewish modest garb.HOW DID I feel as an American Jew walking around with a family of yarmulkes and tzitzit? I got some stares, to be sure. And truth be told, on the night that France won the World Cup semifinal and my daughter and I walked around a very rowdy Nice, there were some stares at my yarmulke that might have been interpreted as menacing.But contrast that with the following story. I was walking in Saint-Tropez with my kids just as the World Cup Final was beginning, and a French private World Cup party found us and put tricolor paint on our faces. And there we were, clearly identifiable American Jews who had suddenly been transformed into fans of “Les Bleus.” Two hours later, as France erupted like a volcano upon their 4-2 victory against Croatia, we were swept up into the celebrations, as people all around broke into “La Marseillaise,” lit flares, jumped into the water, sang some more and doused us in champagne.And how did it feel, for a brief moment, to be both French and overtly Jewish? Well, it felt like it’s something that could be pulled off, if only people could always live at the pinnacle of joy that comes from a World Cup victory.It’s been 20 years since France won the World Cup, and there’s no question that its victory has brought together an otherwise fractured nation. What the nation must now do is solidify the momentary unity that comes from a sporting event to the permanent unity that comes from a nation that believes in liberty, equality and fraternity.It is utterly unacceptable that Jews in France should feel unsafe. The government must enforce the strictest penalties against all antisemitic attacks, and it must safeguard Jewish areas to the highest degree. It must also teach about the Holocaust in all French schools – the French were official collaborators with the Nazis, once they had been defeated – and the French government must always embrace a strong alliance with Israel. French Muslim leaders must preach love and friendship with their fellow sons of Abraham, and brook no incitement in the name of Islam toward Jewry.But alongside all that, there must also be a stalwart decision on the part of French Jews to proudly wear their Jewishness on their sleeves.This past Sabbath I spoke at the Chabad shul in Cannes. I addressed this exact issue. I lectured about how 75 years ago, the Jews of Europe were forced to wear yellow badges of shame. Today, we can choose to wear kippot, proud symbols of our connection to God. And in so doing, we go from being a secret society of people who share a common faith and common values to a visible people, charged by history and destiny with being a light unto the nations.The writer “America’s Rabbi,” whom The Washington Post calls “the most famous rabbi in America,” is the international best-selling author of 32 books, including Lust for Love, co-authored with Pamela Anderson. Follow him on Twitter @RabbiShmuley.