It is now almost three years since I moved with my family to the United States. Life for a Jew in the USA is markedly different to the European experience. American Jews are proud of being Jewish, understandably, and project that pride without equivocation. The idea that you would take off your kippa to avoid anti-Semitism, for example, is a complete anathema to American Jews, although removing your kippa in public is absolutely normal for a Jew in Europe. American Jews are deeply entrenched in the political system as Jews, and they show public support for candidates who advocate for Jewish causes and for Israel. In Europe, Jews involved in politics constantly hedge their views so that they are seen as neutral on “Jewish issues.”I have discovered that American voters, including Jews, feel that it is their right and duty to actively engage in political issues to ensure that the right candidates are elected to public office, or in other words, people who represent the views of those who vote for them, and support them. Every voter is expected to lobby, and Jews do so with vigor and in full public view. In the case of Israel, the Jewish lobby, made up of tens of thousands of unpaid citizen lobbyists, namely Jewish and pro-Israel Christian voters, argue that their cause is not just good for them, but for the national interests of the United States as a whole.Very soon after I arrived in Los Angeles I became involved with AIPAC. This incredible organization runs an annual Policy Conference in Washington, DC, attended by more than 14,000 people. This past March, I led a group of high school kids from Los Angeles to the conference, as part of an effort to educate teenagers about their civic rights, that include the right to lobby for issues they care about right at the heart of government. Our group of 40 boys and girls – the largest high school group to attend – met with multiple senators and congressmen, and attended sessions addressed by US Secretary of State John Kerry and Prime Minister Binyamin Netanyahu.THE FINAL session at the conference was attended by almost every member of Congress. As I sat there listening to unashamed public support for Israel by Jews and non- Jews, all of them senior politicians and leading public figures, and as I listened to the thunderous applause that followed each pro-Israel soundbite, I was struck by how such an event could simply never happen in the UK.No British cabinet minister would stand up in front of 14,000 people and say that the future of his country is tied to the future of Israel. No British Christian leader would declare that “Israel is not the problem – the problem is the Arab rejection of Israel’s right to exist!” Even 25 years ago that would have been unbelievable. Today it would be totally impossible.That’s when the penny dropped. To be a Jew in the UK and in Europe is to be constantly defensive and apologetic, hoping against hope that the non-Jews will continue to tolerate us even if we love and support Israel, and even if we have Jewish-sounding names. It dawned on me that as the memory and guilt of the Holocaust slips ever further into history, the age-old European anti-Semitism, dormant for decades, has re-emerged and is growing, like a cancerous tumor eagerly destroying any healthy tissue in its way.European Jews might say that there have never been more children attending Jewish day schools, and that Jewish social and communal life in Europe is thriving and vibrant. And they might point out that in the United States things are not perfect either. College campuses across the US are rife with student groups advocating for BDS, and President Barack Obama is largely perceived as being far less supportive of Israel than his immediate predecessors were. But such a reaction is naïve and misguided.Life in pre-war Europe, in countries such as Holland, Belgium, France and Hungary, was thriving and vibrant too. They had schools, synagogues, cultural centers, yeshivot, and every other kind of communal organization and institution. In fact they had far more than exists in Europe today.Of course historical analogies are never very accurate, as no two situations are absolutely alike. It is certainly true that mainstream politicians in Europe, unlike the politicians of the pre-war period, are extremely wary of anti-Semitism, and it is not politically acceptable to propose the persecution of Jews. But, frankly, from my vantage point here in Los Angeles it seems that power is inexorably ebbing away from mainstream European politicians. This is most evident in France where, notwithstanding any public criticism by French leaders of anti-Semites, it is clear that the streets of France belong to Muslim hate-mongers. Muslim demonstrators frequently chant, “France is ours, France belongs to us!” and many French Jews believe that it won’t be long before this prediction becomes a reality.France is sleepwalking into a reverse takeover by Islamic fanatics, much as Germany allowed itself to be hijacked by the Nazis, and Russia allowed itself to become the bastion of autocratic communism.Which brings me to my final point. Europe has shown that it is powerless to address the rise of Islamic assertiveness and aggression. We are seeing changes occur that threaten the national identities of European nation states.No one is immune, and certainly not my own country of birth, the United Kingdom, where a marriage of convenience between Muslim fanatics, the hard Left, right-wing anti-Semites and anti-war campaigners has seen the growth of a multi-headed anti-Semitic hydra that it would be folly to dismiss or ignore.Almost 10 years ago, when dangerous anti-Semitism first reared its ugly head in France, and the late Ariel Sharon suggested that French Jews should move to Israel, I wrote an article arguing that for the Jews of France to move to Israel as a way of staying safe would be foolish, seeing as Israel remains in the crosshairs of some of the most evil people on the planet, and – at a time when Israeli Jews were being regularly massacred by suicide bombers – perhaps French Jews would be wiser to stay put.But it was I who was foolish. The one country in the world that has proved time after time that it is willing to defy every kind of taboo, and to use all its resources, to defend the life of any and every Jew, not just in Israel, but across the world, is the State of Israel. And incredibly, the one western democracy that understands this fully, and supports it unequivocally, is the United States of America.So, unless I am missing something, or a miracle occurs, the writing is on the wall for the Jews of Europe. The indigenous citizens of Europe should beware. Jews are always the canary in the mineshaft. The weakness of democracy and its ideals is its tolerance for any creed and ideology, even if they undermine the very democracy that allows them to be expressed and acted out. Even as Europeans pat themselves on the back for having a system that allows reactionary Islamic hate preachers and their odious followers to terrorize the streets, they are thoughtlessly presiding over the decline of the very system they celebrate, and that they fought so hard to establish. I am hopeful, though, that by the time France, Germany and, yes, even the UK have become countries governed by Sharia law, the Jews will have long gone.The writer is the rabbi of the Beverley Hills Synagogue.