Kissinger’s metaphysics comprised equal parts gloom and glee. The gloom was reflected in his belief that experience, life itself, was ultimately meaningless and that history was tragic.“Experience is always unique and solitary,” he wrote in 1950. “Life is suffering, birth involves death.” As to “history,” he said he believed in its “tragic element.” “The generation of Buchenwald and the Siberian labor-camps cannot talk with the same optimism as its fathers.” The glee came from embracing that meaninglessness and tragedy, from the realization that one’s actions were neither predetermined by historical inevitability nor governed by a higher moral authority. There were “limits” to what an individual could do, “necessities,” as Kissinger put it, imposed by the fact that we live in a world filled with other beings. But individuals possess will, instinct, and intuition—qualities that can be used to expand their arena of freedom.

Kissinger, in the obituaries to come, will be called a “realist.” That would be accurate, if realism is defined as holding a pessimistic view of human nature and a belief that power is needed to impose order on anarchic social relations.

But if realism is taken as a view of the world that the “truth” of facts can be arrived at from observing those facts, then Kissinger was clearly not a realist. Rather, Kissinger often declared himself in favor of what today the right denounces as radical relativism: There is no such thing as absolute truth, he argued, no truth at all other than what could be deduced from one’s own solitary perspective. “Meaning represents the emanation of a metaphysical context,” he wrote; “every man in a certain sense creates his picture of the world.” Truth, Kissinger said, isn’t found in facts but in the questions we ask of those facts. History’s meaning is “inherent in the nature of our query.”

This kind of subjectivism was in the postwar air, and Kissinger in his early writings sounded not unlike Jean-Paul Sartre, whose influential lecture on existentialism was published in English in 1947 (and cited by Kissinger in The Meaning of History). When Kissinger insisted that individuals have the “choice” to act with “responsibility” toward others, he sounds absolutely Sartrean, echoing the radical French philosopher’s belief that, since morality isn’t something that is imposed from without but comes from within, each individual “is responsible for the world.” Kissinger, though, took a very different path than Sartre and other dissenting intellectuals, and this is what made his existentialism exceptional: He used it not to protest war but to justify waging it.

Kissinger wasn’t alone among postwar policy intellectuals in invoking the “tragedy” of human existence and the belief that the best one can hope for is to establish a world of order and rules. George Kennan, a conservative, and Arthur Schlesinger, a liberal, both thought human nature’s “dark and tangled aspects” (in Schlesinger’s words) justified a strong military. The world needed policing. But both men (and many others who shared their tragic sensibility like Reinhold Niebuhr and Hans Morgenthau) eventually became critical, some extremely so, of American power. By 1957, Kennan was arguing for “disengagement” from the Cold War, and by 1982, he was describing the Reagan administration as “ignorant, unintelligent, complacent and arrogant.” The Vietnam War provoked Schlesinger to advocate stronger legislative power to rein in what in 1973 he would call the “imperial presidency.” Not Kissinger.

At every single one of America’s postwar turning points, moments of crisis when men of good will began to express doubts about American power, Kissinger broke in the opposite direction. He made his peace with Nixon, whom he first thought was unhinged; then with Ronald Reagan, whom he initially considered hollow; and then with George W. Bush’s neocons, despite the fact that they all rose to power attacking Kissinger; and finally with Donald Trump, whom Kissinger fancifully imagined as the realization of his belief that the greatness of great statesmen resides in their spontaneity, their agility, their ability to thrive on chaos, on, as Kissinger wrote in the 1950s, “perpetual creation, on a constant redefinition of goals.”

“There are two kinds of realists,” Kissinger wrote in the early 1960s, “those who manipulate facts and those who create them. The West requires nothing so much as men able to create their own reality.” Trump, the reality-show president, certainly creates his own reality. A “phenomenon,” Kissinger called Trump, saying that “something remarkable and new” might emerge out of his presidency.

Rockefeller to Nixon, Nixon to Reagan, Reagan to George W. Bush, George W. Bush to Trump: Fortified by his uncommon mix of gloom and glee, Kissinger never wavered. The gloom led him, as a conservative, to privilege order over justice. The glee led him to think he might, by the force of his will and intellect, forestall the tragic and claim, if only for a fleeting moment, freedom. “Those statesmen who have achieved final greatness did not do so through resignation, however well founded,” Kissinger wrote in his 1954 doctoral dissertation; “It was given to them not only to maintain the perfection of order but to have the strength to contemplate chaos, there to find material for fresh creation.”

Kissinger’s existentialism laid the foundation for how he would defend his later policies—policies that brought death, destruction, and misery to millions of people. If history is already tragedy, and life is suffering, then absolution comes with a world-weary shrug. There isn’t much any one individual can do to make things worse than they already are.

Before it was an instrument of self-justification, Kissinger’s relativism was a tool of self-creation and hence self-advancement. Kissinger was skilled at being all things to all people, particularly people of a higher station: “I won’t tell you what I am,” he said in his famous interview with Oriana Fallaci, “I’ll never tell anyone.” The myth about him is that he disliked the messiness of modern interest-group politics, that his talents would have been better realized had they been unencumbered by the oversight of mass democracy. Really, though, it was only because of mass democracy, with its near endless opportunities for reinvention, that Kissinger was able to climb the heights.

A product of the new postwar meritocracy, Kissinger quickly learned how to manipulate journalists and cultivate elites, to whom he made himself indispensable, and leverage public opinion to his advantage. Within a remarkably short period of time, and at a stunningly young age (he was 45 in 1968 when Nixon asked him to be his national security adviser), he had seized the national security apparatus from the establishment “Eastern men.” The gentile WASPs, with their inner-directed egos, like Nixon’s first secretary of state, William Rogers, whom Kissinger eventually pushed out, had no idea what they were up against.

Still, as we consider the world Kissinger leaves behind, it is important to focus not on his outsize personality but on the outsize role he played in postwar history. Since the end of World War II and the beginning of the Cold War, there have been many versions of the national security state. But a transformative moment in the evolution of that state occurred in the late 1960s and early ’70s, when Kissinger’s policies, especially his secretly launched four-year war in Cambodia, hastened its disintegration, undermining the traditional foundations—elite planning, bipartisan consensus, and public support—on which it stood. Kissinger, along with Nixon, welcomed this disintegration: “We’ve got to break the back of this generation of Democratic leaders,” Kissinger told Nixon, as the two men plotted to use foreign policy for domestic advantage. Nixon responded that “we’ve got to destroy the confidence of the people in the American establishment.”

“That’s right,” Kissinger answered.

Yet, even as the breakup of the old national security state was proceeding apace, Kissinger helped with its reconstruction in a new form: a restored imperial presidency based on ever-more-spectacular displays of violence, more intense secrecy, and an increasing use of war and militarism to leverage domestic dissent and polarization for political advantage.

America’s wars in Southeast Asia destroyed the ability to ignore the consequences of Washington’s actions in the world. The curtain was being drawn back, and everywhere, it seemed, the relationship of cause and effect was coming into view: in the reporting by Hersh and other investigative journalists on US war crimes; in the scholarship of a new questioning generation of historians; in documentary films like Emile de Antonio’s In the Year of the Pig and Peter Davis’s Hearts and Minds; among apostate former true believers, like Daniel Ellsberg; in the dissent of intellectuals like Noam Chomsky. Worse, the sense that the United States was a source of as much bad as good in the world began to seep into popular culture, into novels, movies, and even comic books, taking the shape of a generalized skepticism and anti-militarism.

Kissinger helped the imperial presidency adapt to this new cynicism. He was a master of advancing the proposition that the policies of the United States and the violence and disorder that exist outside its borders are entirely unrelated, especially when it came to accounting for the consequences of his own actions. Cambodia? “It was Hanoi,” Kissinger writes, pointing to the North Vietnamese to justify his four-year bombing campaign of that neutral nation. Chile? That country, he says in defense of his coup-plotting against Salvador Allende, “was ‘destabilized’ not by our actions but by Chile’s constitutional president.” The Kurds? “A tragedy,” says the man who served them up to Saddam Hussein, hoping to turn Iraq away from the Soviets. East Timor? “I think we’ve heard enough about Timor.”

Also useful to the armoring of the imperial presidency was what we might call Kissinger’s imperial existentialism, which helped restore a denial mechanism, a way to neutralize the torrent of information becoming available to the public regarding US actions in the world—and the often unhappy results of those actions. Reporters and academics might dig up hard-to-argue-with facts that proved that the overthrow of any given democratic government or the funding of repressive regimes generated blowback. But Kissinger never wavered in his insistence that the past shouldn’t limit the US’s range for options in the future. Great powers, like great men, are absolutely free—free from not only moral oversight but also causal logic that might link past actions to current problems.

Obituaries will mention how conservative hostility toward Kissinger’s policies—détente with Russia, opening to China—helped propel Reagan’s first real bid for the presidency in 1976. And they will draw a distinction between his brand of supposed hardheaded power politics and the neoconservative “idealism” that led us into the fiascos of Afghanistan and Iraq.

But they’ll likely miss the way Kissinger served as not just a foil but also an enabler for the New Right. Over the course of his career, he advanced a set of premises that would be taken up and extended by neoconservative intellectuals and policymakers: that hunches, conjecture, will, and intuition are as important as facts and hard intelligence in guiding policy; that too much knowledge can weaken resolve; that foreign policy has to be wrested out of the hands of experts and bureaucrats and given to men of action; and that the principle of self-defense (broadly defined to cover just about anything) overrules the ideal of sovereignty. In so doing, Kissinger played his part in keeping the great wheel of American militarism spinning ever forward.

No former national security adviser or secretary of state has ever wielded as much influence after leaving office as Kissinger, and not just through his constant advocacy for war (including in Panama and the Persian Gulf). Reagan appointed Kissinger to his presidential committee on Central America, which justified Reagan’s hard line in the region; George H.W. Bush named many of his protégés, including Lawrence Eagleburger and Brent Scowcroft, to top foreign policy posts; and Bill Clinton drew on Kissinger’s help to push NAFTA through Congress.

Kissinger Associates, a private consulting firm, profited from the fallout of Kissinger’s public policies. In 1975, for example, Kissinger, as secretary of state, helped Union Carbide set up its chemical plant in Bhopal, India, working with the Indian government and helping secure a loan from the Export-Import Bank of the United States to cover a major portion of the plant’s construction. Then, after the plant’s 1984 chemical-leak disaster, Kissinger Associates represented Union Carbide, helping to negotiate, in 1989, a $470 million out-of-court settlement for victims of the spill. The payout was paltry in relation to the scale of the disaster, which caused nearly 4,000 immediate deaths and exposed another half million people to toxic gases. In Latin America and Eastern Europe, Kissinger Associates helped broker what one of its employees called the “massive sale” of public utilities and industries, a sell-off that, in many countries, was initiated by Kissinger-supported dictators and military regimes.

Kissinger is, of course, not singularly responsible for the evolution of the US national security state into the perpetual motion machine that it today has become. That history, starting with the 1947 National Security Act and running through the Cold War and now the War on Terror, comprises many different episodes and is populated by many different individuals. But Kissinger’s career courses through the decades like a bright red line, shedding spectral light on the road that has brought us to where we are now, from the jungles of Vietnam and Cambodia to the sands of the Persian Gulf to deadlock in Ukraine to moral bankruptcy in Gaza.

At the very least, we can learn from Kissinger, who unhesitatingly supported Gulf War One and Gulf War Two, and every war between and since, that the two defining concepts of United States foreign policy—realism and idealism—aren’t necessarily opposing values; rather, they reinforce each other. Idealism gets us into the quagmire of the moment; realism keeps us there while promising to get us out; and then idealism returns anew both to justify the realism and to overcome it in the next round. So it goes.