If defensive realists are mistaken to assume that “balancing” potential hostile hegemons is the normal behavior of most states, rather than “bandwagoning” with the threatening power to appease it or “buck-passing” (hoping other powers will do the hard work of thwarting the bully), then the case that the United States can significantly scale down its military budget and minimize its alliances without any major loss in security may seem risky, even to those not engaged in “threat inflation” on behalf of Pentagon and other foreign policy bureaucracies.

To offensive realists and defensive realists, “restraint” means different things. The Massachusetts Institute of Technology scholar Barry Posen has made the most impressively detailed contemporary case for defensive realism in Restraint: A New Foundation for U.S. Grand Strategy. Like Mearsheimer, Posen rejects liberal hegemony. But Posen goes beyond Mearsheimer to reject hegemony in any form as a legitimate goal of U.S. grand strategy.

Earlier this year in an essay in Foreign Affairs, Posen wrote:

Breaking with his predecessors, Trump has taken much of the “liberal” out of “liberal hegemony.” He still seeks to retain the United States’ superior economic and military capability and role as security arbiter for most regions of the world, but he has chosen to forgo the export of democracy and abstain from many multilateral trade agreements. In other words, Trump has ushered in an entirely new U.S. grand strategy: illiberal hegemony.

Defensive realist proponents of a scaled-down foreign policy of “offshore balancing” want a grand strategy other than U.S. hegemony in any form, liberal or illiberal. In 2016, Mearsheimer himself co-authored an essay in favor of offshore balancing with another leading realist thinker, Stephen Walt in Foreign Affairs. But the logic of Mearsheimer’s offensive realist approach might lead one to conclude that some version of what Samuel Huntington in a 1993 essay in International Security called “international primacy” is preferable not only to liberal hegemony, which risks doing too much, but also to offshore balancing, which risks doing too little, too late in response to the rise of a regional or global hegemon outside of North America. Indeed, in their essay Mearsheimer and Walt argue that their version of offshore balancing would preserve American primacy.

This is Mearsheimer’s own conclusion in The Great Delusion:

Moreover, realism dictates that the United States should seek to remain the most powerful state on the planet. It should maintain hegemony in the Western Hemisphere and make sure that no other great power dominates its region of the world, thus becoming a peer competitor. Still, a foreign policy based on realism is likely to be less warlike than one based on liberalism.

On examination, then, the proposed American strategic alternatives of “restraint” or “offshore balancing” are defined in varying ways by different realists. Proving that the logic of structural realism extends to academic international relations departments, the success of American realist thinkers in overthrowing the dominant liberal hegemonic consensus would likely be followed by conflict among the former allies.

In addition to internal disagreements, a factor that is likely to limit the influence on American foreign policy of a “restraint” school is the focus of most academic realists on traditional military threats to the neglect of trade, economic development and industrial policy. To be fair, neorealists do pay attention to industrial capability as one of a number of attributes that would qualify a great power as a “pole” in a system. But with some exceptions, including the late Robert Gilpin, American international relations (IR) thinkers have not had much to say about industrial development.

That is surprising, given the obsession of practitioners of realpolitik throughout history with improving the economic capacities of their city-states, empires or nation-states. From Alexander Hamilton through Henry Clay to Abraham Lincoln and William McKinley, tariff-based import substitution and national infrastructure development along with foreign policy were united in a plan to turn the United States into a major power, equal or superior to industrial Britain. Protectionist economic nationalism was also central to the realist strategies of Otto von Bismarck and the Meiji reformers. Far from being based on free trade and labor mobility, the world economy in the period studied most by academic neorealists—from the seventeenth century to 1945—was the heyday of mercantilism and colonialism, in which trade wars and military wars were treated as legitimate and complementary tools of strategy. If you list famous Western realists—Hamilton, Benjamin Disraeli, Bismarck, Charles de Gaulle—you will not find a free trader among them.

LIBERAL SCHOLARS tend to ignore this history, except as a chronicle of sins and errors to be deplored. The entire liberal project, as Mearsheimer notes, has been based on a vision of atomistic individuals interacting freely in a society which, in theory, should encompass the entire human race in the form of a free global market as well as supra-national institutions in other realms. The utopian goal of liberalism—a post-national, integrated global economy—has been shared with liberals by Marxist socialists, who, however, add the fantasy of international working-class solidarity against “bourgeois” nationalism. Rejected by liberals and socialists alike, the defense of economic nationalism and state-sponsored industrial capitalism has been left to realists—with the striking exception of IR departments in U.S. universities.

Why? The answer, I think, must be sought in the evolution of the U.S. research university after World War II. At that time in economics departments, neoclassical economics—a simplified, highly mathematical version of nineteenth century economic liberalism—marginalized rival traditions, including the more pragmatic tradition of historical or institutional economics identified with various kinds of economic nationalism and developmentalism.

At the same time, in the 1950s, 1960s and 1970s, American neorealism as a discipline emerged as a reaction against prewar international relations schools, which had been dedicated to idealistic schemes for world leagues, world courts and the like. Influenced by “classical realists,” many of whom were continental European refugees like Hans Morgenthau and Henry Kissinger, American neorealists in IR departments sought to develop rigorous and systematic theories of realism which met the standards of positivist American social science, unlike the belletristic and aphoristic wisdom literature penned by the classical realist Herr Professors.

So it was that academic neoclassical economics and academic neorealism divided the world among them. Neoclassical economics ignored war and diplomacy and neorealists ignored trade, immigration, finance and state-sponsored industrialization, subjects left to the IR discipline of international political economy, which, however, approached them with a liberal rather than nationalist bias. Academic economics was based on stylized thought experiments involving generic firms or individuals; in the next seminar room, much IR theory was devoted to similar abstract thought experiments about “polarity.” Drawn toward the idea of explaining society in terms of the action of social forces or structures on individuals, neoclassical economists and defensive realists in different ways fetishized equilibrium—defined as the clearing of prices in economics and as more or less automatic power-balancing in world politics. Push an element of the system, and it will wobble until balance is restored.

Within the post-1945 American university system, in which the prestige of a discipline increases the more it resembles physics, trying to turn messy world politics into a parsimonious social science may have been a good career move. But academic neorealists, in their focus on states as coherent, rational actors, have been woefully blind to the centrality of integrated transnational empires and blocs in world politics.

In an essay in this magazine entitled “Blocpolitik,” this author has made the case that it is impossible to understand contemporary relations among, say, the United States, Germany and Japan on the assumption, shared by classical realists and neorealists alike, that they can be treated as similar independent, “full-spectrum” states. Instead, Germany and Japan continue to be both semi-sovereign states, dependent on U.S. military protection and economically specialized in manufacturing in an American-led bloc. The European Union, with its Franco–German core, is itself a lesser hierarchical bloc within the larger hierarchical bloc led by Washington. As the hegemon of the bloc, the United States specializes in unique services to its dependents, including not only unreciprocated military protection, but also the provision of a common currency and access to the American market to the exports of other bloc members, often to the detriment of America’s own manufacturers. The fact that the American Cold War alliance system did not dissolve after the Cold War can be explained by the thesis that, by 1989, it had ceased to be a traditional military alliance and had become a deeply-integrated military-industrial bloc—a quasi-federation bound together by supply chains and administered, in the United States and its dependencies, by officials who could not imagine their nations existing outside of the Pax Americana.

There is no evidence that Donald Trump wishes to disintegrate the highly-integrated American bloc he inherited from his predecessors. Instead, his goal appears to be to force American military dependencies to contribute somewhat more to bloc defense, while somewhat rebalancing the distribution of manufacturing within the bloc in favor of American producers—two objectives, it should be noted, that he shares with earlier presidents. In the Trumpist version of realism, it seems that this rebalanced American bloc incorporating the industrial triad of North America, Europe and East Asia—not the United States alone—will respond to China’s challenge on all fronts, economic as well as military.