The system has depended, however, on will, capacity, and coherence at the heart of the liberal world order. The United States had to be willing and able to play its part as the principal guarantor of the order, especially in the military and strategic realm. The order’s ideological and economic core order—the democracies of Europe and East Asia and the Pacific—had to remain relatively healthy and relatively confident. In such circumstances, the combined political, economic, and military power of the liberal world would be too great to be seriously challenged by the great powers, much less by the smaller dissatisfied powers.

In recent years, however, the liberal order has begun to weaken and fracture at the core. As a result of many related factors—difficult economic conditions, the recrudescence of nationalism and tribalism, weak and uncertain political leadership and unresponsive mainstream political parties, a new era of communications that seems to strengthen rather than weaken tribalism—there has emerged a crisis of confidence in what might be called the liberal enlightenment project. That project tended to elevate universal principles of individual rights and common humanity over ethnic, racial, religious, national, or tribal differences. It looked to a growing economic interdependence to create common interests across boundaries and the establishment of international institutions to smooth differences and facilitate cooperation among nations. Instead, the past decade has seen the rise of tribalism and nationalism; an increasing focus on the “other” in all societies; and a loss of confidence in government, in the capitalist system, and in democracy. We have been witnessing something like the opposite of the “end of history” but have returned to history with a vengeance, rediscovering all the darker aspects of the human soul. That includes, for many, the perennial human yearning for a strong leader to provide firm guidance in a time of seeming breakdown and incoherence.

This crisis of the enlightenment project may have been inevitable. It may indeed have been cyclical, due to inherent flaws in both capitalism and democracy, which periodically have been exposed and have raised doubts about both—as happened, for instance, throughout the West in the 1930s. Now, as then, moreover, this crisis of confidence in liberalism coincides with a breakdown of the strategic order. In this case, however, the key variable has not been the United States as the outside power and its willingness, or not, to step in and save or remake an order lost by other powers. Rather it is the United States’ own willingness to continue upholding the order that it created and which depends entirely on American power.

Sobering, from this Brookings Institution piece.

I don't know enough about history as a subject to judge the prognostication of historians and think tanks like Brookings. How to assess political realism as an explanatory theory? Perhaps some readers have a better sense of its predictive power.

All of it can seem like macroeconomics, maddeningly theoretical and imprecise. And yet the best of it has the appeal of strong narrative, which we humans love so much. It's too bad the story here, which seems quite plausible, is so bleak.

There is no stable balance of power in Europe or Asia without the United States. And while we can talk about soft power and smart power, they have been and always will be of limited value when confronting raw military power. Despite all of the loose talk of American decline, it is in the military realm where U.S. advantages remain clearest. Even in other great powers’ backyards, the United States retains the capacity, along with its powerful allies, to deter challenges to the security order. But without a U.S. willingness to use military power to establish balance in far-flung regions of the world, the system will buckle under the unrestrained military competition of regional powers.

If history is any guide, the next four years are the critical inflection point. The rest of the world will take its cue from the early actions of the new administration. If the next president governs as he ran, which is to say if he pursues a course designed to secure only America’s narrow interests; focuses chiefly on international terrorism—the least of the challenges to the present world order; accommodates the ambitions of the great powers; ceases to regard international economic policy in terms of global order but only in terms of America’s bottom line narrowly construed; and generally ceases to place a high priority on reassuring allies and partners in the world’s principal strategic theaters—then the collapse of the world order, with all that entails, may not be far off.