Why was there rising antisemitism in late-19th-century Europe, and how did the Jews react to it? Most significant in explaining the rising antisemitism is that there was rising nationalism at the same time and in the same places—well, most significant besides the emancipation of the Jews, which started with the French Revolution. The rising antisemitism was in part a symptom of the rising nationalism. Many Jews of that time reacted to the antisemitism-nationalism with Zionism, which is a kind of Jewish nationalism: not, say, the Jewish-German or Jewish-French kind of nationalism, but the Jewish-Israeli kind of nationalism.

Rising nationalism culminated in the World Wars. At the end of World War One, there were four empires in ruins: the German Empire, the Austro-Hungarian Empire, the Russian Empire, and the Ottoman Empire. From those ruins emerged many nationalities who wanted their own nation states. The Zionists agreed with the zeitgeist of the time: that each nationality should rule itself instead of some nationalities ruling over other nationalities. The antisemitism-nationalism was antisemitic only insofar as the Jews, who were their own nationality, were living among other nationalities. The Zionists agreed: The Jews too should separate themselves. The Jews too should have their own nation state. Most important to understand is that it’s not that the Jews were singled out. For example: Analogous to the anti-Jewish sentiment in, say, Germany and Austria after World War One, there was anti-ethnic-German sentiment at the same time and for the same reason. That is, there was anti-ethnic-German sentiment against the ethnic Germans living outside of the new borders of Germany and Austria. There was hatred against every nationality living outside of its own nation state. Zionism’s answer to the Jewish question was to treat it as one of the many national questions.

Other Jews of that time reacted to the antisemitism-nationalism with Marxism, which argued that it’s not national distinctions that matter but class distinctions. For example—according to Marxism—a German proletarian can relate to a French or Russian proletarian more than they can relate to a German bourgeois. People should identify not with their nationality but with their class.

To go back to the emancipation of the Jews: Emancipation led to a different, non-nationalism-based antisemitism. The ghettoized Jews, segregated from the Christian majority in where they lived and given only a few options for work (e.g., moneylending), were tolerated most of the time. Only here and there did violence break out. But emancipation led to an explosion of Jewish influence on Gentile society, which in turn led to an explosion in the intensity of the Gentile’s long-standing love-hate relationship with the Jews. Pre-emancipation, the love-hate relationship was: “The Jews are useful to the economy, e.g. in doing the moneylending. But we’re jealous of how much money they have.” Post-emancipation, the love-hate relationship came to a head because of the newfound Jewish influence in science, philosophy, music, etc. Emancipation desegregated Jewish influence. It freed the Jews to make much more wide-ranging contributions. But it was only some of the Gentiles who appreciated that. Many Gentiles, especially in Germany, argued that the Jewish “contributions” were in fact not contributions at all. The old antisemitic-anticapitalist argument, which was that the traditional Jewish economic success was fraudulent, was extended. The new antisemitic argument charged the Jews with fraud not only economically but also in science, philosophy, music, etc.

With all of that said: The Jews reacted to the rising antisemitism in late-19th-century Europe, which (as I explained above) was because of nationalism and emancipation, in several ways:

1. Some Jews gave up on Europe and left. Most of those Jews went either (a) to America or (b) to what later became modern Israel.
2. Other Jews didn’t give up on Europe. (a) Some of those other Jews swam with the current of emancipation, despite its at-least-short-term antisemitic effect. They believed in assimilation. For example, the Jewish-German assimilationists believed in thinking, feeling, and acting German. Antisemitism was because of incomplete assimilation. Antisemitism would die with complete assimilation. (b) Other Jews who didn’t “give up” on Europe—well, they did give up on the society of Europe—swam against the current of emancipation. They retreated back to the ghettos. They ghettoized themselves anew. The outside world used to be shut to them, but when it opened up they didn’t like what they saw. They shut it back out themselves.
3. Some of the Jews who swam with the current of emancipation swam against the current of nationalism. Marxism was popular among such Jews.
4. Among the Jews who agreed with nationalism, there were (a) the assimilationists, (b) the non-assimilationists, and (c) the Zionists. For example: (a) The “Jewish-German” assimilationists downplayed or even got rid of the “Jewish” part of their identity. They wanted to be “German” like everybody else—at least that’s what they wanted in public, for in private many of them kept their Jewish identity. (b) The “Jewish-German” non-assimilationists were comfortable with being “Jewish-German.” They wanted to keep both parts of their identity. And (c) the “Jewish-German” Zionists sidestepped the question. They gave up on Germany.
5. In reply to the antisemitic-anticapitalist argument, which had long charged the Jews with economic fraud, some Jews (in the majority) argued for socialism and other Jews (in the minority) argued for capitalism. The socialist Jews in effect replied: “Yes, our people have been greedy. They’ve been exploitative. Antisemitism was for that reason unavoidable. But that’s only because of capitalism. If we get rid of capitalism, then we get rid of the possibility for that greed and exploitation.” And the capitalist Jews in effect replied: “No, our people haven’t done anything wrong. In fact, our people’s economic success has been everybody’s economic success. Capitalism brings everybody more wealth than they’d otherwise have.”