“The fiercest arguments we have in parliament are over Israel.” These words, spoken by the chairman of the Dutch Foreign Affairs Committee, startled me. But they failed to faze the other committee members from the both the left and right. On the contrary, they all readily agreed. In the end, only I displayed surprise.

“Let me get this straight,” I said. “Your country is in economic crisis, tens of thousands of refugees are massing on your borders, and the EU may be unraveling, and yet the issue that most occupies you is…Israel?”

My hosts unanimously nodded. However shocking, the conversation was by no means unusual. As chairman of the Foreign Affairs Subcommittee in Israel’s Knesset, I frequently meet with European legislators.

Whether Dutch or Belgian or German, they all report the same phenomenon. Israel—more than security, more than refugees, and the economy—sparks their bitterest debates. And each time I hear this, I find myself astonished. At stake, I realize, is not Israel’s identity but the Europeans’. For them, the Jewish State is exactly that, a state of Jews against whom the West is once again defining itself.

So it has been for more than two thousand years. The ancient Hellenic and Roman worlds, challenged theologically by a Judaism that rejected their polytheism and the divinity of kings, and threatened demographically by burgeoning Jewish populations, designated the Jews as the ultimate Other.

The first large-scale pogroms and expulsions took place in Rome and Alexandria well before the birth of Christianity. “How could one consider admitting such a people to citizenship or allowing them political rights?” Apion, a first century anti-Semite, wrote. “The Alexandrians were right in detesting the Jews.” By the early second century, Alexandria’s Jewish community, once a million-members strong, had all but vanished.

Pagan Europe’s efforts to define itself in opposition to the Jews intensified as the continent came under the Church. In contrast to the spiritually chosen, temporally strong, and philanthropic Christians, Jews were portrayed as Christ-killers, damned to statelessness and materialism. Just as, after the destruction of the Second Temple in 70 CE, Roman coins showed a proud legionary holding a spear over a humbled Jewish woman, medieval cathedrals portrayed Ecclesia lording a spear-like cross over a cowered Jewish woman.

And, as in ancient Judea, the otherness of the Jews justified their expulsion. “We must avoid making ourselves partners in their devilish ranting and raving by shielding and protecting them,” Martin Luther wrote in 1543. “One should toss out these lazy rogues by the seat of their pants.” Indeed, by time of the Renaissance, much of Western Europe was Judenrein .

The Enlightenment scarcely changed this situation. As David Nirenberg revealed in his epic study Anti-Judaism: The Western Tradition , Enlightenment thinkers were obsessed with Jews and Jewishness. From the French Revolutionary Assembly to the philosophy of Hegel, Kant, and Schopenhauer, Europeans debated at length whether the Jews were even fully human, much less worthy of citizenship.

Emancipation was eventually achieved but only after bitter disputations that in many cases never really ceased. The Dreyfus trial that began a century after France freed its Jews was not, in fact, about Dreyfus but about France—whether the country would be liberal and secular or militantly Catholic. Marx singled out Judaism as the antithesis of Communism. For Hitler, Jews were the non-Aryans par excellence.

But, whether in ancient Rome or 20th-century Munich, the Jews remained necessary. Without them, Europeans were at pains to specify who they were and were not. And that role continues today. Just as anti-Semitism in Europe was pre-Christian, so, too, has it persisted after the European Union ruled out Christianity as one of the sources of European identity. The same Dutch government that is offering dozens of its national churches for sale is acridly divided over Israel’s policies toward the Palestinians.

While grappling with a failed economy and massive security threats, French leaders have time to launch a Middle East peace initiative that Israel rejects. Addressing the European Parliament this month, Palestinian President Mahmoud Abbas repeated a medieval European libel by accusing Jews of poisoning Palestinian wells. Abbas later apologized, but the Europeans gave him a standing ovation.

Europe’s continuing fixation on Jews indeed presents challenges to Israel, and yet the far greater danger is that the obsession could grip the United States. The debate over Israel is increasingly becoming a debate over America. In the current elections, especially, pro-Israel platforms are associated with a muscular view of U.S. foreign policy, a strong stand against Islamic extremism, and a willingness to assume world leadership.

Conversely, positions described as “even-handed” on Israeli issues are likely to be accompanied by a recoiling from military force, dependence on the U.N. and other international organizations, and a focus on domestic matters.

“Israel has to remind America what it is,” a member of a visiting Congressional delegation recently told me.

Even more than with the European legislators, my reaction was one of surprise—along with alarm. “No,” I replied. “Americans do not need Israel to define themselves.” And the Jews, I thought, do not need to serve as crucibles for yet another nation’s identity. In Europe, that role resulted in incalculable suffering for my people and continues to plague us today.

America, I hope, has the self-confidence to determine by itself its place in the world, to debate its future openly and even rigorously, but without reference to the Jews and our nation-state.

Michael B. Oren, formerly Israel’s ambassador to the U.S. and a member of Knesset (the Israeli parliament), is the author of Ally: My Journey Across the American-Israeli Divide.