As part of the Hans Kelsen Visiting Professorship, funded by the Alfred Landecker Foundation, Miloš Vec researches the emergence and codification of international law. His work focuses in particular on the 19th century as a formative phase of the international order—a time in which key principles, institutions, and ways of thinking took shape that remain valid or continue to have an impact today. In the interview, Vec discusses how international law developed as a discipline and why it is worth re-examining its history.
Professor Vec, international law is currently experiencing a resurgence due to numerous geopolitical conflicts. At the same time, many people who would not normally engage with the subject now refer to it. What is the most common misconception about international law that you would like to dispel?
MV: In addition to the misconception that international law is not really law, many people are surprised when I tell them how old international law actually is. In public awareness, events of the 20th century are particularly prominent: the Treaty of Versailles, the Nuremberg Trials, the United Nations. Some people are also familiar with the Peace of Westphalia of 1648. In fact, however, the earliest evidence of peace agreements or border arrangements between autonomous political entities such as city-states can already be found in Mesopotamia—they are more than 4,000 years old. And this immediately raises another fascinating question: what arguments support calling this international law—and what arguments speak against it?
Your current research focus deliberately distances itself from day-to-day political issues and instead concentrates on the history of international law from the 18th to the 20th century. What makes this period so central to our present-day understanding of international law?
MV: This seemingly distant relationship between legal history and contemporary politics quickly disappears when we look at global legal principles. Researching the emergence of the international legal order is not an apologetic endeavor—on the contrary, it often involves historical critique of law. Behind the enduring nature of legal norms, we frequently find considerations of justice that originate in the modern era. And since the modern world emerged over the past two centuries, it is no surprise that today’s international law has been shaped by these developments: the “statization” of the world (whereby political entities adopt this fundamental organizational form), as well as its “juridification.” International relations have increasingly been governed by customs and treaties, and courts also decide on conflicts. This predictability and the transformation of power struggles into questions of justice have a long and important tradition in international law. Much of this developed slowly, some of it suddenly; and some aspects remain highly contested—as current debates about the legality and legitimacy of humanitarian interventions in international law demonstrate.
In your view, what role does the perspective play from which one approaches the history of international law? Or, put differently: what distinguishes, for example, a European perspective from an American one?
MV: The legal culture of the United States, with its common law tradition, differs significantly from that in Europe. This concerns, for example, the relationship between precedent and written law, the self-understanding of legal professionals, and the role of legal scholarship and universities. These differences can be described historically and are also reflected in how rules of international law are handled. At the same time, certain parallels have emerged in recent decades: for a long time, the historiography of the “West” has been challenged by feminist, postcolonial, and subaltern perspectives. The latter, particularly in the context of decolonization, have developed their own views on imperialism and colonialism and have examined the lasting impact of these processes on both continents and on international law. Today—intensified by a growing transatlantic divide—numerous differences are becoming apparent even within this so-called West. The historical self-understanding of the current U.S. administration under Trump, for example, turns away from critical historiography and even relativizes the injustice of slavery.
You speak of a global history of international law. What role do non-European actors and normative orders play in your research?
MV: An increasingly important one! I am particularly pleased that more and more students are taking an interest in these questions and that related research projects are being developed at my chair in Vienna. For example, one project examines how the Mixed Courts in Egypt shaped the domestic application of the law of war. But gaps do not only exist outside Europe—within Europe itself, regions such as the Balkans or Eastern Europe are often underrepresented in our historiography. One of my doctoral students, for instance, is studying Hungarian international legal scholarship in the interwar period. All of this shows that today’s global international law has a wide range of legal and political predecessors. Even outside Europe, there were regional autonomous orders in which international law played a role in regulating relations between states. Trade, transportation, and diplomatic communication were shaped by these systems, and perhaps also warfare. The extent to which this was the case can only be determined on a case-by-case basis. Historians often face immense challenges, as for some regions and periods there are far fewer sources than one would wish for—or sometimes none at all.
Why did you choose to focus your monograph on Wolfgang Preiser? What particularly interested you about his work on the origins of international law?
MV: The book on the historian of international law Wolfgang Preiser (1903–1997) was, in a way, the result of several coincidences. As a student, without ever having met him, I collected materials for him from the Frankfurt University Library. At that time, he was already emeritus but continued to read and write with great curiosity. Later, I began working on the history of international law myself, and one day I was asked to write a portrait for the 25th anniversary of his death. The deeper I delved into archival materials, publications, and accounts by contemporaries, the clearer it became that Preiser’s history of international law was also a response to the Nazi state. He searched in distant historical periods and outside Europe for traces of what he identified as “international law,” presenting it as a bulwark against pure exercises of power. His work was an ethical legal history—but not a history of progress.
If you had to highlight one key idea from your research: what should we understand about the history of international law in order to better interpret current global conflicts?
MV: International law does not mean that the supposed law of the strongest prevails. Instead, there are participatory mechanisms—for example, through what we now describe as civil society, through international organizations, or through non-state actors—to shape norms, demand their implementation, or at least make violations visible. International law will always be shaped by questions of power, but power alone is not sufficient. The justification of political action is a necessity. Such justifications can be moral, theological, or of another nature; today, they are primarily articulated in the language and grammar of law. The tension between power and law, however, remains. Powerful actors seek to interpret international law in their own interests, to reshape it—or to circumvent it. Looking to the past provides a rich reservoir of experiences and stories about injustice and justice. Each generation revisits this history from its own perspective, seeking new interpretations and answers.
Do you already know what you will focus on next?
MV: The book I am currently completing in Cologne is an edited volume on the Congress of Vienna (1814/15) and international law: a continent reorganizing its legal order after a major war. There is more law than ever before. However, the aim is not only to secure peace, but also to preserve the existing political order within states. Popular participation and constitutionalism are seen as dangerous and are to be suppressed—international law is also mobilized for this purpose. Instead, what emerges is an international order shaped by crowned heads. They invoke hereditary rights and Christianity. At the same time, they seek to combat the international slave trade, simplify river navigation, and modernize diplomacy. Once this project is completed, I plan to turn to a concise, textbook-style account of the entire history of international law.