In his classic 1951 book American Diplomacy, Cold War strategist George F. Kennan rethought not only his own views but also those of American policymakers from the 1898 war with Spain to the outset of the Cold War. The book was comprised of six lectures delivered in 1951 at the University of Chicago under the auspices of the Charles R. Walgreen Foundation. A newly expanded edition, published by the University of Chicago, adds an 11,000-word introduction by University of Chicago (there is a trend here) political scientist John Mearsheimer, as well as two of Kennan’s Foreign Affairs essays (from 1947 and 1951) and his 1984 reflections on the Chicago lectures, along with a foreword he wrote for an edition of the book that year.

Kennan’s Walgreen Lectures have been called “the most famous series of lectures ever delivered on American diplomacy” by Cold War historian Melvyn Leffler, who believed that nothing Kennan subsequently wrote matched their impact. Indeed, Foreign Affairs called them “for many years the most widely read account of American diplomacy in the first half of the twentieth century.” Yet their influence has waned over the years, not because the Kennan’s thinking has aged poorly but because the appetite among the public and policymakers for Kennanesque views has declined.

Kennan had been at the summit of policymaking before he delivered these lectures. He had served several diplomatic tours in the Soviet Union, including a stint as deputy chief of mission under Ambassador Averell Harriman from 1944 to 1946. While sick in bed that year—the man was frequently ill, in part due to anxiety problems—he dictated to his secretary an analysis of Soviet behavior that the State Department had requested. Kennan’s exposition came to 8,000 words, far more than State had had in mind. He admitted years later that it was an “outrageous encumberment of the telegraphic process,” but he believed it was necessary to convey his views accurately.

The “Long Telegram” became famous. Suffice to say it offered a persuasive, eloquent, historically grounded explanation for the sources of Soviet conduct and American strategy to counter the threat. “My reputation was made,” Kennan recalled in his Memoirs. “My voice now carried.” Indeed, he became instrumental in forging America’s postwar foreign policy, helping to devise the Marshall Plan along with aid to Greece and Turkey and providing the framework for the containment strategy that, in mutated form, served as the basis for U.S. policy throughout the Cold War.

His influence was at its zenith under Secretary of State George Marshall—and declined swiftly under Marshall’s successor, Dean Acheson. Kennan took a leave of absence in 1950 and soon thereafter delivered the lectures. Under Acheson, he recalled, he had been “relegated to the sidelines” and “outside the chain of command, one step removed from the real decisions.” Acheson had merely tolerated him: “he was, I suspect, sometimes amused, sometimes appalled, usually interested; but there were times when I felt like a court jester, expected to enliven discussion, privileged to say the shocking things, valued as an intellectual gadfly on hides of slower colleagues, but not to be taken fully seriously when it came to the final, responsible decisions of policy.” Acheson, for his part, recalled that he once told Kennan he ought to quit the Foreign Service and go “preach his Quaker gospel but not push within the Department.”

So much for the context of the lectures. Kennan’s purposes in delivering them, he wrote in the first (“The War With Spain”), was to explain why America in 1900 was “so secure … [and] had relatively little to fear,” yet by 1950 was “insecure” and faced conditions “dangerous and problematical in the extreme … hemmed in as we are by a thousand troubles and dangers, surrounded by a world part of which seems to be actually committed to our destruction and another part to have lost confidence either in ourselves or in itself, or in both.”

What is striking about these sentences is that they contradict Kennan’s sentiments not only in some of his other writings but also in other passages of American Diplomacy. Even in the same lecture, he argued, “in 1900 we exaggerated the security of our position and had an overweening confidence in our strength and our ability to solve problems, whereas today we exaggerate our dangers and have a tendency to rate our abilities less than they actually are.” Kennan oscillated between optimism and despair. His ambivalence was perhaps best revealed in a note he sent to Acheson before he left government, at a moment when the Korean War had begun to go south—or more accurately, north, above the 38th parallel dividing the two Koreas and that the U.S. military had now crossed, only to find the Chinese entering the war. Kennan wrote:

In international, as in private, life what counts most is not really what happens to someone but how he bears what happens to him. For this reason almost everything depends from here on out on the manner in which we Americans bear what is unquestionably a major failure and disaster to our national fortunes. If we accept it with candor, with dignity, with a resolve to absorb its lessons and to make it good be redoubled and determined effort … we need lose neither our self-confidence nor our allies nor our power for bargaining. But if we try to conceal from our own people or from our allies the full measure of our misfortune, or permit ourselves to seek relief in any actions of bluster or petulance or hysteria, we can easily find this crisis resolving into an irreparable deterioration of our world position—and of our confidence in ourselves.

Such self-doubt mixed with confidence in America’s capabilities pervades American Diplomacy.

Another matter on which Kennan was of two minds was American democracy. Exasperation at its failings flows continually though his work, as he ascribes the failures of U.S. foreign policy to lawmakers’ deference to popular opinion. In American Diplomacy, he calls this “diplomacy by dilettantism.” He would have preferred a corps of professional officers to have unrestrained power to make foreign policy. He famously compared democracy to “one of those prehistoric monsters with a body as long as this room and a brain the size of a pin.” Such lines were not aberrations but part of his lifelong thought. “There is, let me assure you, nothing in nature more egocentrical than the embattled democracy,” he wrote in his 1960 book Russia and the West Under Lenin and Stalin. “It soon becomes the victim of its own war propaganda.” Even historian John Lukacs, in his admiring 2007 biography called simply George Kennan, conceded that Kennan’s criticisms of democracy intermittently progressed into hatred, “something that even his friends and admirers ought not to ignore.”

Yet Kennan also writes in American Diplomacy, “The system under which we are going to have to continue to conduct foreign policy is, I hope and pray, the system of democracy.” And while he believed public opinion in the short term is “easily led astray into areas of emotionalism and subjectivity which make it a poor and inadequate guide for national action,” he also wrote, “I do not consider public reaction to foreign-policy questions to be erratic and undependable over the long term.”

The best one can say is that Kennan was not dogmatic about democracy. Indeed, he was dogmatic about very little. One is struck by how little theory or ideology occupied his mind. He was generally identified as a “realist” in the mold of Hans Morgenthau, and he maintained a fruitful correspondence with the godfather of American realism. The two shared the view that a state’s primary task is to preserve its national interest—Kennan wrote in American Diplomacy, “our own national interest is all that we are really capable of knowing and understanding.” Both also eschewed romanticism in policymaking. Perhaps the most famous lines in Kennan’s lectures are that he “see[s] the most serious fault of our policy formulation to lie in something that I might call the legalistic-moralistic approach to international problems.” He opposed attempts to apply domestic concepts of justice to the international arena. Not because he was amoral; just the opposite: “it is a curious thing, but it is true, that the legalistic approach to world affairs, rooted as it unquestionably is in a desire to do away with war and violence, makes violence more enduring, more terrible, and more destructive to political stability than did the older motives of national interest.”

But even as a realist, Kennan was sui generis. In his first Walgreen talk, Kennan faults one thinker for falling prey to the “overestimation of economics, of trade, as factors in human events and … the corresponding underestimation of psychological and political reactions—of such things as fear, ambition, insecurity, jealousy, and perhaps even boredom—as prime movers of events.” Most other realists “underestimate” those explanations too: they see international affairs as the raw product of competition for power in an anarchic world; domestic factors affect the international struggle only in exceptional circumstances. And while Kennan had a lifelong hatred of nuclear weapons, most realists today believe they prevented the Cold War from becoming a hot one.

Kennan may have the better approach—at the very least, it is better that policymakers have specialized knowledge than adhere to any theory, even the best of which will have imperfections and gaps. Whereas the only thing that men like John Foster Dulles knew about the Soviets was that they wore red and fought bears, Kennan could connect their behavior to Peter the Great’s. He was, as a result, brilliantly able to discern what secretive governments like Stalin’s were after. He understood that the Soviets’ motives were a mixture of Marxist ideology and typical great-power ambitions. Mearsheimer believes Kennan was incorrect in seeing ideology, not the will to power, as the source of Soviet behavior, but the two could not be separated in Kennan’s view. The Soviets needed Marxism to provide ideological rationalizations for their immoral, tyrannical actions. “That is why Soviet purposes must always be solemnly clothed in trappings of Marxism, and why no one should underrate the importance of dogma in Soviet affairs,” he wrote in the Long Telegram.

He extracted larger lessons from his own experiences abroad. He warned in American Diplomacy against “the acceptance of any sort of a paternalistic responsibility to anyone, be it even in the form of military occupation, if we can possibility avoid it, or for any period longer than is absolutely necessary.” In his Memoirs he echoed his hero Gibbon’s remark that “there is nothing more contrary to nature than the attempt to hold in obedience distant provinces.” He learned this, he wrote, from his scrutiny of Nazi Germany’s problems as an occupying force.

Kennan did not fully acknowledge the power of nationalism, however. (Mearsheimer astutely points out that the word barely appears in American Diplomacy.) Among the great tragedies of World War I, he wrote, was that it dissolved the Austro-Hungarian Empire, and thereby allowed Germany to dominate Europe. But it was simply an illusion to believe that the Hapsburg Empire could survive; the wonder is that it existed as long as it did, as Gibbon said of the Roman Empire. Twelve main nationalities and some 15 language groups comprised the empire, a deeply unstable polity in a post-1848 world. Similarly, Kennan writes that both World Wars “were fought, really, with a view to changing Germany; to correcting her behavior, to making the Germans something different from what they were.” He wrote that “If you tried to compute the various degrees of guilt,” for World War I, “you got a rather fuzzy pattern: the Austrians and the Russians no doubt in first place, the Germans with less but certainly with a goodly share … . Above all, you could not say that anyone had deliberately started the war or schemed it.”

May/June 2013 issueHis was the popular view well into the 1960s, epitomized by the success of Barbara Tuchman’s Pulitzer Prize-winning 1962 book, The Guns of August. We now know it to be false. In 1959, Fritz Fischer was the first historian to publish findings from the archives of Imperial Germany. He discovered that in fact Germany did want a war, and it simply exploited the assassination of Archduke Franz Ferdinand to realize its ambitions to dominate Europe. As Philip Bobbitt wrote in The Shield of Achilles, after Fischer’s work, it is “impossible to maintain” that the war was a “ghastly mistake” and not of Germany’s design. Kennan was unable to see that Germany, once reunified by Bismarck, could not be contained without war.

American Diplomacy’s most enduring, brilliant insight was perhaps its definition of the U.S. interest in world affairs: that “no single Continental land power should come to dominate the entire Eurasian land mass.” Should one do so, it would enter “on an overseas expansion hostile to ourselves and supported by the immense resources of the interior of Europe and Asia.” Preventing that is all the U.S. needed. And so it remains. The only difference is that now China, not Russia, Germany, or Japan, poses the greatest challenge.

Everything Kennan ever wrote is worth reading. As Lee Congdon argued in his fine 2008 book, George Kennan: A Writing Life, part of what makes the Milwaukee-born diplomat so compelling is the sheer beauty of his prose—few other historians come close to matching its gorgeousness, which seems to come from his deep reading of great works of fiction. (He would have liked to have been a novelist.) But of course, what makes us go back to Kennan’s works decades after the Cold War are his enduring insights into American foreign policy. That few Americans read him today says more about the public than it does about Kennan. To profit from his genius, American Diplomacy is the best place to start.

Jordan Michael Smith is a contributing writer at Salon and the Christian Science Monitor.