Some of the most important 19th-century nationalists were in fact cosmopolitans, who considered the national order to be universal and sought to carry their fights across borders. The most famous among them was the revolutionary Giuseppe Mazzini, who spearheaded the movement for the unification of Italy and fought in other national struggles across Europe. Promoting an international association of nations, his People’s International League stood for “the rights of nationality” and a “cordial understanding between the peoples of all countries.”

Even as nationalists radicalized, beginning at the turn of the 20th century, growing more and more chauvinistic, anti-liberal and authoritarian, they did not give up their internationalist ambitions. Following the October Revolution in Russia, nationalists, ranging from centrist conservatives to far-right extremists, united against the perceived left-wing threat. Many fought within their countries, but most considered their battles as part of a global struggle.

One of the key thinkers of this right-wing international was Nicholas Murray Butler, the conservative president of Columbia University. In his 1918 tract “A World in Ferment” he drew a distinction between “colloidal" — i.e., cosmopolitan — and “crystalline” internationalism.

Butler dismissed colloidal internationalism as the “hopelessly impractical" desire by liberals and the left for “a worldwide community without national ties or national ambitions.” In contrast, crystalline internationalism was based on “nationalistic and patriotic sentiments and aims,” which are “elements in a larger human undertaking of which each nation should be an independent and integral part."

One of the early organizations to emerge in this vein was the Geneva International, founded in 1924, with sections in 18 countries as far away as Australia. Devoted to “defending the principles of order, family, property and nationality” around the world, its cosmopolitan networks included figures like Spain’s Francisco Franco and France’s Philippe Pétain — and it reached out to Benito Mussolini and Adolf Hitler.

Europe’s Fascist movements between the world wars engaged in various forms of international cooperation, including a series of world congresses. The most important was the Conference of Fascist Parties in Montreux, Switzerland, convened by Mussolini in 1934, which was to forge a transnational coalition in the struggle against socialism and liberal democracy. All of the major Fascist regimes held their own international meetings, and invited fellow Fascist parties to events inside their countries. At their Nuremberg rallies, the Nazis welcomed like-minded groups from Iraq, Siam (modern-day Thailand) and Bolivia.

The regimes also founded several internationalist organizations to engage with Fascist movements around the world. “Fascism is now an international movement, which means not only that the Fascist nations can combine for purposes of loot, but that they are groping, perhaps only half-consciously as yet, towards a world system,” observed George Orwell in 1937.