Former Bosnian Serb leader Radovan Karadzic stands in a courtroom during his initial appearance at the U.N.’s Yugoslav war crimes tribunal in The Hague on July 31, 2008. (Jerry Lampen/AP)
Edin Hajdarpasic is a historian of modern Europe at Loyola University Chicago. He is the author of "Whose Bosnia? Nationalism and Political Imagination in the Balkans, 1840-1914."

In 1993, when I arrived in America as 16-year-old Bosnian Muslim refugee, I quickly realized that most Americans had little understanding of what kind of political catastrophe drove my family out of our country. Sure, the media duly reported on massacres, broken truces and renewed negotiations among Bosnian Serb, Muslim and Croat factions. Then the explanations would inevitably devolve into a jumble of unfamiliar names and bizarre ideas.

Throughout the 1990s, men like Radovan Karadzic, the Serbian politician and convicted war criminal who faces final sentencing at the International Criminal Tribunal for the Former Yugoslavia today, and Slobodan Milosevic would briefly appear on the American evening news. They would ramble about avenging medieval losses to Muslim invaders only to segue into sanitized talk of territorial partitions, population exchanges and European values. These men directed the horrors that my family fled from. And as touchstones for anti-Muslim and anti-immigrant movements, they continue to inspire white supremacist violence to this day.

To understand the current wave of global extremism, we need to understand how national movements fuse with transnational ones — how calls of America First or Australia First are part of a global White People First movement. And to understand that, there is no better place to begin than the place where I was born: Bosnia.

When American friends would ask me to explain the bewildering scenes from Bosnia, I remember trying to describe the insidious descent of nationalism on my country, only to encounter the assumption that it couldn’t happen here. I would tell people that no one really expected Karadzic, a ridiculously bad poet and psychiatrist obsessed with perceived Serb victimhood, to win enough votes, let alone organize a genocidal movement seeking ethnic purity. Yet that is what happened over the course of less than a decade.

How tragic, how senseless, most people would tell me. It’s so complicated, others would say. Some would assure me I had nothing to fear in America. It apparently had a system of checks and balances that would prevent the rise of such extremism. Besides, well-meaning advice went, you’re here now. The crazy things that happened over there are so, so far away.

As a refugee, however, I learned the hard way that what you think is safely over there is already here. As a historian, I’ve learned not to look to the past for exact analogies — there are none — but to ask questions and explore connections that can help us rethink the present.

One starting point for understanding the international nature of converging nationalist and extremist mobilization is the simple fact that it predates the Internet.

Since the 1930s, nationalist, fascist and far-right politicians from Eastern Europe to Latin America have been learning from one another and dreaming of a new world composed of similarly “pure” nations. Nazism, too, had international rather than exclusively German origins. Not only was Hitler influenced by Italian fascists, but Nazi ideologues also took copious notes on the key institutions of American racism. As historian James Q. Whitman has shown, Nazi policymakers were fascinated with American anti-miscegenation and citizenship laws, applying the lessons they learned to Germany. In turn, many aspiring extremists across interwar Eastern Europe and Latin America selectively copied and improvised upon these developments, contributing to a loose, incoherent but globally available fascist repertoire of similar myths and tactics.

This transnational dimension remains fundamental to the character of far-right mobilization today, even as the technologies, strategies and targets of these movements have profoundly changed. While weaponizing algorithms and social media platforms, different cohorts of nationalists, neo-fascists and other extremists continue to look to one another for examples, support and inspiration across the world. In the process, they are improvising new globally available templates for recruitment narratives and actions.

The recent fusion of Serbian and white nationalist tropes is a telling example of this transnational history of extremism.

During the 1990s, Karadzic promoted organized violence against Bosnian Muslims with a slew of grotesque narratives. To his Serb supporters, Karadzic peddled stories of impending doom at the hands of bloodthirsty and aggressively reproducing Muslims in Bosnia and Kosovo. The only remaining defense against Serb demographic decline, Karadzic claimed, was preventive violence to separate the different ethnic groups.

Anxious to impress the West by cloaking murder in respectable garb, Karadzic and his cronies often played on the idea of a global “clash of civilizations.” Full-time conspiracy theorists like Srdja Trifkovic have made international careers telling tall tales of Serb nationalists as defenders of a civilized West against a Muslim tide from the East.

It’s not hard to see how these extremist ideas — and the violent acts that accompanied them — would find a new home in the flourishing Islamophobic movements of the 21st century. Since the 2000s, an array of white supremacists and other aspiring extremists worldwide have seized on these Karadzic-era myths, retooling them in racial terms, demonizing Muslims and non-white “immigrants” and disseminating such ideas for further imitation and improvisation.

For Anders Breivik, the Norwegian terrorist who killed 77 people in a 2011 attack, Karadzic was not just another crusader from the distant past but a living idol, someone he aspired to meet. Brenton Tarrant, the suspect in last week’s massacre in New Zealand, also paid homage to Karadzic alongside other Christian European “defenders” against a tide of Muslims and more generally non-white “immigrants.” Like Breivik, Tarrant spent a significant portion of his manifesto retracing and updating Karadzic’s fantasies, from the Muslim demographic threat to the need for preventative violence against non-white “invaders.” He even made several trips from his native Australia to the Balkans since 2016, apparently searching for inspirational sites of Ottoman-era battles. Online and in real life, he found a global cohort of allies who eagerly stoked his violent fantasies.

To be clear, the incoherent but incendiary mishmash of conspiracies, myths and memes behind these attacks do not have Serbian — or for that matter uniquely French, American or Australian — origins. Far from having any single-country origin, the history of such extremist movements shows us that they thrive on global connectivity and mutual imitation. As a recent investigative report shows, contemporary Serbian nationalists are collaborating with far-right British contacts, who in turn develop new strategies of recruitment for extremist causes elsewhere in Europe and the United States. This is the norm, not the exception, in the history of such movements.

Nationalist politics are never confined to any one country, no matter how remote or obscure. Nationalism always involves international mobilization of different social elements linked by similar views, often conspiracy theories and appeals to violence for defense of national interests or racial purity.

Understanding the contemporary appeal of nationalism and white supremacy as inextricably linked problems is essential to any effort to defeat these movements.

Put another way, we must resist the comforting but false thought that the violent ideologies behind organized mass murder will somehow just stay in New Zealand, in Bosnia or somewhere “over there.” They are already here.