The first antisemitic parties organized internationally from the start.

Evidence

And not only the Nazis, but fifty years of antisemitic history, stand as evidence against the identification of antisemitism with nationalism. The first antisemitic parties in the last decades of the nineteenth century were also among the first that banded together internationally. From the very beginning, they called international congresses and were concerned with a co-ordination of international, or at least inter-European, activities. — Hannah Arendt, The Origins of Totalitarianism, 61

Categorization

• SEED: Potential essay angle: ‘the transnational morphology of exclusionary ideologies’ — tracking how antisemitism, and later pan-European fascisms and contemporary anti-Muslim movements, organize across borders.
• XREF: Connects to the imagined-community/nation-building toolkit: exclusionary ideology pre-dates and transcends the nation-state frame.