HENRY KISSINGER, who recently turned ninety-seven, is America’s most celebrated living statesman. None of his successors has come close to matching the extraordinary blend of acclaim and notoriety, admiration and criticism that he attracted as national security adviser and secretary of state to Richard M. Nixon and secretary of state to Gerald Ford. The British Foreign Office referred to him at the time as “the Wizard of the Western World'” and Playboy Bunnies voted him the man they would prefer to date in 1972—no small accomplishments for an expert on the Congress of Vienna who spent much of his early career at Harvard, where his cohort included the likes of Samuel Huntington, Stanley Hoffmann, and Zbigniew Brzeziński.

But Kissinger’s foreign policy wizardry was always accompanied by reproaches and rebukes, both public and private. The posthumously published The Letters of Arthur Schlesinger, Jr., for example, reveal that in a lengthy November 5, 1974 missive to Kissinger, Schlesinger expressed his dismay to his old friend about the direction of American foreign policy during the Nixon administration:

I cannot but feel that our foreign policy in recent years removed the United States from what historically has been the source of our greatest impact on mankind. We have most influenced the world as a nation of ideals, conveying a sense of hope and faith in democracy… It may well be said that such hope was often delusory and that it often concealed a tough sense of American self-interest. […] The conception of world affairs as a chess game played by foreign secretaries contains an instinctive preference for authoritarian states, where governments can be relied on to deliver their people, as against democracies, where people might always turn on their governments.

The Left and Right united in attacking him as an amoral practitioner of realpolitik who had subverted American ideals: to the former he was a war criminal who had wantonly deployed American power abroad; to the latter, an appeaser who had not deployed it enough. Ronald Reagan declared at the Republican Convention in Kansas City in 1976 that “Henry Kissinger’s recent stewardship of U.S. foreign policy has coincided precisely with the loss of U.S. military supremacy… Under Kissinger and Ford this nation has become No. 2 in military power in a world where it is dangerous—if not fatal—to be second best.”

Kissinger was undaunted. His two volumes of memoirs, which were published in 1979 and 1982, were bestsellers. In 2014, in a poll of American international relations scholars, he was named the most effective secretary of state in the previous fifty years. He has remained a coveted presence in the Oval Office, advising presidents from Jimmy Carter to Ronald Reagan, from George W. Bush to Donald Trump. Vice President Dick Cheney said, “I probably talk to Henry Kissinger more than I talk to anyone else.” Kissinger also advised Hillary Clinton when she was secretary of state, observing “She ran the State Department in the most effective way I’ve ever seen.” Clinton reciprocated the sentiments in a 2014 review in the Washington Post of his book, World Order: “Kissinger is a friend and I relied on his counsel when I served as Secretary of State.” Yet in 2016, when she ran for the Democratic nomination, she became embroiled in a nasty dispute with her rival Bernie Sanders over her admiration for Kissinger. Sanders declared during a debate in February, “I am proud to say Henry Kissinger is not my friend” (as though he had a real choice in the matter). Decades after he exited government service, Kissinger continued to provoke disputes about his legacy and reputation.

AS AMERICA lurches wildly in foreign affairs, it seems safe to say that the case for Kissinger is becoming stronger than ever. The belief that America should function as a missionary nation-state, exporting democracy whenever and wherever it chooses, has suffered a brutal buffeting in recent decades, as what once seemed indispensable has begun to look decidedly dispensable, at least when it comes to intervening abroad. Indeed, in Iraq and Afghanistan, hubris has substituted for discernment, folly for strategy. Perhaps, then, it should come as no surprise that realism has begun to come in for a second look in recent years. What was once dismissed as amoral has begun to appear as a higher species of morality. In recent years, a flurry of books has thus started to offer a decidedly revisionist take on Kissinger, extolling his foreign policy acumen and diplomatic prowess. This effort to counter the series of dyslogistic books on Kissinger and to restore a sense of proportion, even—dare one say it?—an equilibrium, in assessing Kissinger may be said to have begun with the historian Niall Ferguson’s recent biography which attempted to depict him as an idealist throughout his career. Now, Barry Gewen, an editor at the New York Times, in a much superior book called The Inevitability of Tragedy, explains why Kissinger’s thinking—his view of history, power, and democracy—should command our attention.

Gewen does not merely come to praise Kissinger, but rather to explicate his intellectual odyssey—from his formative years at Harvard to his immersion in world affairs in Washington to his tutelary role as an elder statesman. Gewen deftly sets him in the wider context of the rise of totalitarianism in the past century, seeking to understand Kissinger as he understood himself. Above all, he knows that realism demands a realistic appraisal of Kissinger. As Gewen puts it,

He is more than a figure out of history. He is a philosopher of international relations who has much to teach us about how the modern world works—and often doesn’t. His arguments for his brand of Realism—thinking in terms of national interest and a balance of power—offer the possibility of rationality, coherence, and a necessary long-term perspective at a time when all three of these qualities seem to be in short supply.

Perhaps nothing impressed upon Kissinger, much of whose thinking has revolved around the dilemmas of power that plagued central Europe, the importance of a balance of power and the fragility of democracy more than the rise to power of Hitler in January 1933. Hitler was installed by the conservative German elites who loathed Weimar democracy as a Western import that was alien to the true Teutonic spirit and who believed that in Hitler they had discovered a pliant instrument to lay the basis for a return to the old order. They were wrong. Hitler not only destroyed democracy, but also Germany itself. In striving for a new German empire, he reversed Bismarck’s unification of Germany, leaving it sundered, the plaything of Russia and the Western powers. “Hitler’s advent to power,” Kissinger wrote in his masterwork Diplomacy, “marked one of the greatest calamities in the history of the world.” Kissinger, whose family emigrated from Germany in 1938, saw the ease with which a sinister demagogue such as Hitler could turn democratic practices against a democracy. Kissinger himself later recalled, “I had seen evil in the world.” Gewen suggests that these experiences prompted Kissinger to gaze not only with an appropriately wary eye at the export of democracy, but also at America itself. His wariness was shared by others who had fled the Third Reich for America. For prominent thinkers such as Leo Strauss, Hannah Arendt, and Hans Morgenthau, democracy wasn’t an answer, but a conundrum that they tried to address. They, too, had seen that liberal democracy might serve as pit-stop rather than a road block on the path to totalitarian rule. “Government of the people, by the people,” Gewen writes, “is a fine thing when it works. But the fact is, as Kissinger knew so well, frequently it doesn’t.”

It was Kissinger who became the supreme exponent of realpolitik in American foreign policy. In this regard, he drew deeply upon the work of Morgenthau, who considered Kissinger one of the greatest secretaries of state in American history. “We shared almost identical premises,” Kissinger once wrote. They remained lifelong friends, and in 1983 Arthur M. Schlesinger, Jr., awarded Kissinger the Morgenthau Memorial Award of the National Committee on American Foreign policy, noting that America needed Kissingers and Morgenthaus—intellectuals willing to work inside of government as well as scholars content to remain outside to offer bracing criticisms.

Though Morgenthau was an early opponent of the Vietnam War—in 1965 he asked, “What will our prestige be like if hundreds of thousands of American troops become bogged down in Vietnam, unable to win and unable to retreat?”—he remained steadfast in his admiration for Kissinger’s tenure during the Nixon administration. In his focus on the “national interest” and skepticism about an international community of nations in his classic work Politics Among Nations, Morgenthau influenced a host of realist thinkers, including George F. Kennan, Walter Lippmann, Raymond Aron, and Reinhold Niebuhr. Richard Nixon, too, echoed Morgenthau when he declared, “The only time in the history of the world that we have had any extended period of peace is when there has been balance of power.” America's objective should not be to overcome or subdue tragedy and evil in international affairs but to preserve its freedom of maneuver under the force of circumstance. This was the principle that animated Nixon and Kissinger as they sought to extricate America from Vietnam, forge a détente with Moscow, establish diplomatic relations with China, and seek peace in the Middle East. Had Nixon and Kissinger not successfully improved relations with the Soviet Union, the Cold War would never have come to a peaceful end. Nor would the Camp David accords in 1978 between Israel and Egypt have been possible absent Kissinger’s imaginative shuttle diplomacy in the Middle East.