Senator Bernie Sanders is the candidate for a stronger America of enhanced global influence. He is a sober, clear-eyed, foreign-policy realist. Yet few recognize this, mainly because of his impassioned focus on broad domestic reforms. Most view Sanders as anything but a realist—more like a utopian idealistand concede the foreign-policy advantage to former secretary of state Hillary Clinton or any of the tough-talking Republican candidates. But they are wrong, and the liberal Sanders is paradoxically the only foreign-policy realist in the presidential field.

This comes as a surprise because realism in the popular mind has grown synonymous with overweening might and unilateral assertion of US objectives; think “shock and awe” and “regime change.” Sanders is none of those, and most equate him instead with foreign-policy idealism: allergic to the use of force, and naively trusting in multilateral diplomacy. But these are not Sanders either. Moreover, such simplistic definitions have diverged very far from their original, nuanced meanings, which it behooves us to recall at this most troubled time in international affairs.

Realism as a foreign-policy concept is at least as old as the great-power rivalries detailed in The History of the Peloponnesian War, by the Greek historian Thucydides. The term came into widespread use with E.H. Carr’s The Twenty Years’ Crisis, where he contrasted realism with the utopianism that failed to understand—much less manage—shifts in the interwar balance of power. The balance of power was also a central concern of Hans Morgenthau’s Politics Among Nations, the classic of postwar realism.

Like all realists, Morgenthau emphasized states’ overriding need to guard their security in a “self-help” world—we must always be powerful enough to defend ourselves. But Morgenthau also cautioned against squandering that power, against stumbling into costly conflicts by overestimating threats or underestimating local backlash against our military incursions. Morgenthau’s immediate concern was Vietnam, as America was drawn into a quagmire in part thanks to a false narrative foisted on the public—one that portrayed a long-running conflict in a deeply divided country as a simple matter of communist aggression. Neither did it help that our “nation building” in Vietnam depended on a client who was deeply unpopular in his own country. Substitute Iraq and WMD for Vietnam and Gulf of Tonkin (and perhaps Ahmed Chalabi for Ngo Dinh Diem), and you know what Morgenthau would have said about the crusade to create a “new Middle East.” And you can guess who he’d have judged the better realist: Sanders, who opposed the Iraq War, or Clinton, who supported it as well as promoting the “regime change” that has failed so spectacularly in Libya?

Morgenthau faulted the tendency of great powers to “clothe their own particular aspirations” in arrogant assumptions of moral universality. Hubris is what the ancient Greeks termed it—and Donald Trump is only its loudest devotee among presidential aspirants—as Thucydides chronicled its role in the downfall of Athens, when a reckless overseas adventure, the invasion of Sicily, turned into a military-political disaster. But the Athenians’ larger mistake lay in failing to see how their aggressive rise caused allies to defect and neutrals to rally against them. This is a core realist concept, seen in so many conflicts through history: that states seek to balance against perceived threats.

That the powerful must take care not to provoke was what another famed realist, George Kennan, argued at the Cold War’s end. Kennan, best known as the author of our Cold War containment strategy, warned after the USSR’s collapse of the danger in capitalizing on Russia’s weakness by expanding NATO and pushing the Western military alliance eastward. A prostrate Russia posed no threat, and Kennan correctly foresaw that alienating it by advancing NATO to its doorstep would produce a self-fulfilling prophecy—“a strategic blunder of potentially epic proportions.” He was joined in this opposition by numerous realist scholars, but to no avail. By now, with that prophecy fulfilled, you can also guess where Sanders and Clinton each stood on the launch of NATO expansion in the 1990s.

Kennan also shared Morgenthau’s skepticism of moral crusades abroad, and understood that global influence rests as much on domestic solidarity as military power. America must live up to its own ideals, and show the world “a country which knows what it wants, which is coping successfully with the problem of its internal life…and which has a spiritual vitality.” Upon these depend not only the socio-economic wellsprings of military might, but also the moral authority to lead by example—in modern parlance, soft as well as hard power. With other candidates waving the banner of American exceptionalism, only Sanders is realist enough to sound the alarm that political corruption and deepening inequality have put the domestic foundations of that leadership in real jeopardy.

This returns us to the first and simplest of realism’s precepts—discarding illusion and self-congratulation to see the world as it is, to see ourselves as others see us, to face reality. This means admitting that the post–Cold War designs of both neoconservatives and liberal interventionists have done more harm than good. It means acknowledging the epic disaster of our Mideast policies—of Democratic and Republican presidents alike—and both the regional chaos they have caused as well as the myriad new threats that now radiate out toward Europe, Russia, Africa, and Asia. It also means asking how much stronger would our military be if not for over a decade of wars, thousands of US soldiers killed, and up to 1 million more wounded? And how much more influence might we yield today if the several trillion dollars these wars have consumed had been invested instead in infrastructure or global development?

After frank admission of where we’ve erred in the past, the realist turns next to sober assessment of current and future threats. Global warming, Bernie? Alone among the candidates in putting climate change at the top of that list of threats, Sanders the “idealist” is in fact only highlighting the very realistic warnings of various Pentagon, CIA, and other defense analyses on how global warming has fueled instability and extremism in countries from Nigeria to Syria, and that it constitutes such an “immediate risk,” “threat multiplier,” and “grave challenge” that we ignore at our peril. To call Sanders naïve for this—for drawing attention to such underlying causes as poverty and resource scarcity exacerbated by climate change, instead of indulging in such saber-rattling as “carpet bomb ISIS” and “shoot down Russian planes”—is akin to promoting dubious remedies for the symptoms of a disease while mocking the careful treatment of its causes to forestall a global pandemic.

As urgent as the global challenges of climate change may be, the next US president will face myriad even more immediate crises. Does Sanders propose naïve, idealistic, and radical approaches to them? Not at all. His call for a broader coalition on policy toward Syria—coordinating with Russia and neighboring Muslim states toward a managed transition, to avoid the even-greater chaos that a sudden collapse of the Assad regime would trigger—is in fact the direction in which Washington and our European allies have recently moved. The chances of success, certainly in the near term, are modest at best. But it is also arguably far more “realistic” than the position of Clinton, whose support of a US-policed no-fly zone and greater involvement in Syria threatens another slippery slope toward quagmire. Morgenthau lamented leaders’ inability to learn the lessons of even recent history, and cited a 1970 Wall Street Journal article discussing the fervent “desire to ‘do something’” even when the odds are that it will only make things worse and impedes acceptance of the fact that “the US ability to shape events is often negligible.”

Other issues on which the mainstream has recently moved toward Sanders and not vice versa—at least the “more experienced and pragmatic” Clinton has—include opposition to the Keystone XL pipeline from Canada, drilling for oil in the Arctic, and the Trans-Pacific Partnership trade pact. There is similarly little daylight between Sanders’s and Clinton’s positions on a firm posture toward Russia, including bolstering cooperation with European allies and maintenance of economic sanctions until Moscow fully cooperates in a lasting resolution of the Ukraine crisis. Neither are there major evident differences in their policies toward China—pushing for fairer trade relations, cautiously balancing China’s military buildup in the region, and offering diplomatic support for improved human rights. It is difficult to say if this is the most “realist” policy toward a rising China—but it is certainly much closer than one that threatens a sudden 45 percent increase in tariffs on Chinese imports.

Launching a major trade war, tearing up the Iran nuclear agreement, carpet bombing in Syria—the Republican candidates’ “level of dialogue on national security issues would embarrass a middle schooler,” said former defense secretary and CIA director Robert Gates last month. Donald Trump, Ted Cruz, and the others “are out there making threats and promises that are totally unrealistic.” Senator Rand Paul, who recently dropped out of the race, was arguably the only foreign-policy realist in the Republican field—and was roundly attacked for it. Gates, once much more hawkish himself but now tempered by the experience of recent decades, summarizes the realist critique:

On the left, we hear about the “responsibility to protect” civilians to justify military intervention in Libya, Syria, Sudan and elsewhere. On the right, the failure to strike Syria or Iran is deemed an abdication of U.S. leadership. And so the rest of the world sees the U.S. as a militaristic country quick to launch planes, cruise missiles and drones deep into sovereign countries or ungoverned spaces.

Though Gates may differ sharply with him on domestic policy, Sanders is by Gates’s own criteria probably the only foreign-policy realist left in the presidential race. But many will still question Sanders’s foreign-policy credentials, because realism is still reflexively associated with aggression, and because the image of a utopian-idealist dies hard. The world is dangerous, and a realist must be ready to use force in defense of clear national interests; he or she cannot be a pacifist. Yet in various cases—such as the 2001 war against the Taliban/Al Qaeda in Afghanistan, or the 1999 NATO intervention to halt Slobodan Milosevic’s aggression in the former Yugoslavia—Sanders has not shied from military action. But acting realistically means understanding not just when, but also when not, to employ armed force. As Gates continued:

Wars are a lot easier to get into than out of. Those who ask about exit strategies or question what will happen if assumptions prove wrong are rarely welcome at the conference table when the fire-breathers are demanding that we strike—as they did when advocating invading Iraq, intervening in Libya and Syria, or bombing Iran’s nuclear sites. But in recent decades, presidents confronted with tough problems abroad have too often been too quick to reach for a gun. Our foreign and national security policy has become too militarized, the use of force too easy for presidents. Today, too many ideologues call for U.S. force as the first option rather than a last resort.

Gates is faulting the ideologues of America’s recent Mideast policies, while Morgenthau lamented the “fire-breathers” of the Vietnam War. Now, as then, the “yen for action” (to quote the Journal article cited by Morgenthau) leads to “bold policy as therapy.” And now, as before, once we are engaged in a conflict the issue becomes “not of adapting policy to reality, but of reinterpreting reality to fit policy.” And so for what may be the best of motives—but the worst of judgment—the hawks stand ready to ratchet up confrontations not just in the Mideast, but also from Ukraine to the Arctic and South China Seas.

The leading GOP contenders—Trump and Cruz—advocate highly aggressive policies that have learned nothing from the recent, much less distant, past. Clinton has admitted her “mistake” in voting for the Iraq War, but she still spins her Libya debacle as a success and supports escalating our military involvement in Syria. Her most prized adviser is the venerable Henry Kissinger, the doyen of realpolitik but one who broke with most realists on key policy choices—Vietnam, NATO expansion, and the invasion of Iraq. And so the search for a genuinely realist candidate leads to the unlikeliest of conclusions: the wild-haired democratic socialist from Vermont is, paradoxically, the most clear-eyed foreign policy realist of them all.