This also means greater emphasis on what Kaplan describes as balance and discernment: balance among the tools of American power, the division of labor between the United States and its global partners, as well as between what America does abroad and its priorities at home; and careful discernment about when, where and how America pursues its interests abroad.

When we forget this frontier sensibility, we get ourselves in trouble. In this way, Kaplan aims the mirror on the failings of those of us in the professional elite—the “imperial class” of professional foreign-policy analysts at think tanks, at many universities and in the media. He stresses the dangers of a foreign-policy debate whose answer to nearly every problem is “more.” Doing more of everything, of course, is not a strategy.

This is not to say that Kaplan argues for isolation. Again, the power of America’s geography means leadership is intrinsic to its geopolitical destiny. Yet while the United States should act abroad with ambition and confidence, it also needs to exercise the kind of restraint and sense of limits that were necessary for survival on the frontier, following a practicality that was “about doing rather than imagining and living according to an applied wisdom of common sense.” And therein lies the danger: for if the American public loses trust in its governing elite, believing it to be incompetent or seduced by its own illusions, the result would be disastrous.

In this respect, Kaplan’s outlook is strikingly similar to a leader mentioned only in passing: Barack Obama. He too stressed the importance of U.S. leadership and heralded American exceptionalism, but he also waged a vigorous debate with many of the ideas and impulses that dominate the foreign-policy establishment (as he once put it, “people sitting behind desks in Washington or New York”—or as one of his closest advisers infamously called it, the “blob”). He warned against indulging in either “impetuous or . . . manufactured responses that make good sound bites but don’t produce results.” And he called for a foreign policy rooted in pragmatism and humility—not in fear and weakness, but in confidence and strength. It’s interesting that Obama, the first American president who grew up outside the continental United States, has such a keen sense of the frontier sensibility. Perhaps it is because of his grandparents’ Kansas roots. Or perhaps it is because, like Kaplan, Obama has the gift of close observation.

“To be effective globally,” Kaplan writes, “American leaders must be anchored to their own soil.” But balancing America’s responsibilities at home and abroad is incredibly difficult, and presidents struggle with articulating the right mix of engagement and retrenchment. Obama was roundly criticized for calling for “nation building at home” by those asserting he wanted to withdraw from the world. This was always a gross caricature. But, reflecting on the politics of 2016 and the turmoil today, perhaps the problem has not been too much nation building but too little. Similarly, it was Woodrow Wilson who, exactly a century ago, ran for president with the slogan to put “America First,” only then to champion a bold new vision for remaking world order.

Oddly enough, the cumulative effect of both Kaplan and Smith’s books is renewed optimism—they both serve as reminders of the tumult of the past, and the enduring ways America remains unique. When so much of America’s future seems up for grabs, remembering its shared history and geography is not a luxury. It is essential.

Derek Chollet is executive vice president of the German Marshall Fund of the United States, and author of The Long Game: How Obama Defied Washington and Redefined America’s Role in the World.

Image: This painting portrays settlers moving west, guided and protected by Columbia and aided by technology, and driving Native Americans and bison into obscurity.​ Wikimedia Commons