Great power competition is everywhere these days—in Syria, Ukraine, the South China Sea, North Korea. With the rise of China and the rejuvenation of Russian military power, realist thinking is suddenly back in vogue, as it should be.

Idealism in foreign policy is, by definition, the pursuit of a dreamy vision of a better world that does not seriously ask whether the ideal is actually compatible with reality. Illusions set idealists up for terrible surprises. Addressing problems through, for example, the lens of Fukuyama-style Hegelian idealism, according to which the world is inexorably progressing toward liberal democratic values, would in today’s world be not only absurd but dangerous. The liberal idea that the UN can foster world order through international institutions is likewise naïve and perilous. Fantasy lands in art and literature can be wonderful divertissements, but using them as the basis for great nation’s foreign policy can produce nightmares.  

George W. Bush created a dream world in his mind where it seemed plausible for American military power to end “tyranny in our world.” Tyranny, as anyone who has not slipped the bonds of reality knows, is rooted in the human soul and cannot be “ended.” Tyranny can be checked and mitigated, but only through extraordinary effort and with the help of a rich tradition.

But it is always easier to assign oneself virtue based on self-applauding and unrealistic notions about world peace. When realist thinkers—from Machiavelli to Kissinger—prick the bubbles of the dreamers, they incur only wrath. For idealists, it is the height of cynicism and bad manners to point out that cunning and force are what actually dominate world affairs.

Yet for all their sagacity, realist thinkers are not without their problems either. They tend to deny the moral nature of human beings and the role that this may play in world events. Because they have seen the great danger of moralistic idealism in foreign policy, they sometimes don’t think morality should be considered at all. Realist theory has a cold, inhumane quality that makes it inattentive to the moral dimension of human existence.

The failure of realists to incorporate moral considerations into their thinking has made realism unpopular with the American people, who historically believe that their nation’s foreign policy should have at least some moral content. They, after all, send their own boys and girls to war, and they would like to think that those sacrifices are not made for some mechanistic balance of power. They know that statesmen must often make cold calculations in the national interest, but surely somewhere in there must be right and wrong, as in all human endeavors.

Because some realists have adopted the philosophically untenable position that morality has no role in world affairs, many Americans have signed on with the moralists’ disastrous crusades instead. The realists have the stronger policy case, but they have ceded the moral ground to the idealists.  

Ironically, it may be the work of Henry Kissinger that can show realists an intellectual path toward restoring a sense of morality in foreign policy.

For Kissinger, peace depends upon “a system of independent states refraining from interference in each other’s domestic affairs and checking each other’s ambitions through a general equilibrium of power.” The Peace of Westphalia and, to some degree, the Congress of Vienna embodied such an arrangement, offering the lesson that balance-of-power theory is indispensable in analyzing world events.

However, Kissinger was intellectually astute enough to recognize that, in order to create and maintain this equilibrium of power, something more than a mechanical balance is required: enlightened statesmen. Kissinger states explicitly that balance-of-power “does not in itself secure peace.” If world leaders refuse to play by Westphalian rules, the system will break down. He warns of the rise of radical Islamists, for example, who refuse to think in Westphalian terms.

Kissinger also says that enlightened leaders must not only recognize the realities of power politics and the hard Machiavellian truths of international competition, but possess a certain moral quality that he calls “restraint.” Without a willingness to restrain themselves and to act dispassionately, world leaders will be incapable of building an international order. When facing difficult challenges, enlightened diplomats and statesmen must have the moral courage to accept certain “limits of permissible action.” Implicit in Kissinger’s thought is that morality, though of a realistic kind, is essential in foreign policy. Only statesmen of a certain temperament and moral character can support the Westphalian model.

Morality in foreign affairs, then, is not found in a set of abstract rules of behavior for nation-states, nor is it found in deploying military power to advance some progressive, idealistic cause. Morality can be found only in the souls of righteous statesmen who, under complex international circumstances, act not out of malice or hatred, nor out of greed or pure self-interest, but who find a path to peace that is compatible not only with the interest of their own nations but that of the others. Such a policy cannot be sketched out in the abstract in advance; it can emerge only through the moral leadership of genuine statesmen who act to find a specific solution in a set of complex, concrete circumstances. This is one of the great lessons of classical political philosophy: justice is not an abstraction but found concretely in the soul of the just man.

The answer to the question of what a just and moral foreign policy might look like is that it’s the kind that truly just and moral, but also supremely realistic, statesmen will adopt. That such statesmen are rare is what has caused the great philosophers to lament that only the dead have seen the end of war.

William S. Smith is managing director and research fellow at the Center for the Study of Statesmanship at The Catholic University of America.