Mary L. Dudziak is Asa Griggs Candler Professor of Law at Emory University. She is the author most recently of War Time: An Idea, Its History, Its Consequences.

Will there be “but one heart to the globe?” asks Walt Whitman in a poem that provides an epigraph in Mark Mazower’s new book, Governing the World: The History of an Idea. At the center of this expansive work is the question of how Americans and Europeans have imagined the world, its peoples, and its nations. Is there but one global identity, as Whitman surmises? Are the world’s peoples the focus of global politics, or should nations be privileged in international affairs? Do values and culture, or degrees of civilization, set nations apart? These questions inform global affairs over time. This history matters, Mazower argues, as “we find ourselves… in a hierarchical world in which some states are more sovereign than others.”

Power also matters: For Mazower, dominant nations come to play a role in defining the world. He embeds his narrative in the development of familiar institutions, such as the United Nations, and is especially compelling when he reveals lesser-known stories like the development of common units of measurement, presided over by social scientists in the West. This ambitious and largely convincing account falls short, however, when the author turns to contemporary matters. Disappointed that international law does not adequately constrain American war efforts, he misses an important turn in modern conflict: the way that law itself has been reimagined as a weapon of war.

To make the point that the history of ideas matters to contemporary policy-making, Mazower opens the book with a young Henry Kissinger writing about the Concert of Europe. The Concert, an innovation in global politics in 1815, enabled Austria, Prussia, the Russian Empire, and Great Britain to work together in an effort to contain the revolutionary spirit of France. Emphasizing order over rights and liberty, they saw themselves as speaking for Europe as a whole. Their accord legitimated intervention in the domestic affairs of other European nations. “[R]ight at the start of the history of international institutions,” Mazower writes, “we find states and politicians arguing over the limits of ‘the government of the world.’ ” As for Kissinger, his dissertation topic provided him with “a lesson of enduring value” for America: “What long-dead European aristocrats… could teach the United States was how to constrain a revolutionary superpower—for France read the USSR—and bind it into the rules of the international game.”

A leading scholar of twentieth-century European history at Columbia University, Mazower is at his best in Governing the World when he illuminates the way European and American understandings of global politics unfolded. Works on the history of world governance most often focus on diplomacy, international conflict, and the establishment of institutions like the United Nations. The history of ideas usually appears through the biographies of important leaders like Woodrow Wilson. But Mazower places ideas about the world and its governance at the center of the story, with individuals as the carriers of certain concepts. This makes an otherwise familiar story new and exciting. The author’s central thesis unfolds gradually and implicitly, and his narrative beautifully expounds the shaping role of ideas over time. But Mazower does not share enough of his own thoughts, withholding a more explicit theoretical analysis. That absence might have been intended to make the book appealing for a broad readership—and it is a wonderful read—but it also undermines the book’s power.

The very word “international” emerged in the 1780s, coined by philosopher Jeremy Bentham to distinguish between internal laws and what was then called “the law of nations.” Ideally, for Bentham, international law would promote “the greatest happiness of all nations taken together,” and would be crucial to maintaining peace. Before long, Mazower writes, “ ‘international’ had already become an -ism, a radical project,” which developed along with the rise of representative government. By the mid-nineteenth century, “[i]nternationalism, in its modern sense as a movement of cooperation among nations and their peoples, was moving from the realm of marginal ideas into the mainstream, while monarchy itself was obliged to accommodate itself to the era of large electorates and parliamentary power.”...