FROM TIME to time pundits and professors find themselves enmeshed in remarkably testy disputes about the validity of “realism” in foreign policy. As someone usually seen as a realist, though an inconstant one, I have argued the matter as dutifully as any academic colleague. But is there any good reason for actual policy makers who have to get things done to be concerned with it? Many seem to think so. In the past few years, a number of commentators have pondered whether President Barack Obama fits the mold of realist or idealist.

In one sense the theoretical issue doesn’t matter all that much because in concrete cases, realists do not always provide definite answers, or answers different from those of idealists. Yet the theoretical question remains important because it calls attention to the difference between utilitarian or consequentialist moral concerns on one hand and absolute moral principles on the other—why the former should take priority when they conflict, and how the balance of power should drive states’ choices.

Underlying such debates are two epochal images from the twentieth century: the contrasting paths to war represented by the crises of 1914 and 1938, which demonstrate the dangers of overreacting and underreacting to threats, respectively. Those images have been overworked in the imaginations of both analysts and decision makers. We cannot get beyond them, however, because their visions of mistakes to avoid point in opposite directions, and—contrary to the tendency of many to cite one or the other as the crucial lesson—neither of the two can safely be dismissed. In addition, two other less frequently considered cases from that era deserve more attention than they have gotten as illustrations of where realism prescribes a clearly different course from what many idealists think of as common sense: the Western reaction to the Soviet invasion of Finland in 1939 and Finland’s status during the Cold War.

DOES REALISM tell us what to do? Statesmen have good reason to care about ideas if they offer a practical road to action or inaction. And the most important of questions about what to do is whether to use force or threaten it when a conflict grows. The trouble with realism is that it is not a reliable prescription for actual policy. It is a highly general concept, covering a multitude of sins in its evolution over the centuries. To liberal idealists it connotes a brutally cynical cast of mind and a violent modus operandi in the style of the Borgias, while to neoconservative idealists it represents naively callous appeasement in the mold of Neville Chamberlain. Realism is a vague norm that does not offer consistent strategic guidance. Rather, it is an attitude more than a doctrine, and it has counseled forceful activism in some conflicts, restraint and accommodation in others. In the early Cold War realists were usually seen as hawks, but since then they have been more often viewed as doves. As Matthew Evangelista once noted with more than a whiff of contempt, one might find wanting a theory that has recommended policies as diverse as appeasement and preventive war.

Realism is usually seen as dismissing moral and legal concerns in international politics, while idealists see values and institutions as driving forces. Yet conservative realists like Henry Kissinger put great emphasis on the role of legitimacy and multilateral institutions in world order (for example, the nineteenth-century Concert of Europe), and liberal idealists like Madeleine Albright have often been avid in the use of force and compromised respect for the legal import of sovereignty (as over Kosovo). Neoconservatives, too, who are basically unilateralist liberals when it comes to foreign policy, see concern with power and values not as alternatives but as strategically fused, with military muscle being the necessary vehicle for America’s unique moral right and responsibility. In fact, who does or does not count as a realist in the real world, as compared with the ivory tower, is seldom clear. Is Obama a realist because he reveres Reinhold Niebuhr and sometimes holds the United States back from military adventurism? Or is he an idealist because he sometimes takes counsel from Susan Rice and Samantha Power?

Outside the ivory tower actual policies do not come straight out of any realist or idealist playbook, but from coalitions that cross the theoretical divide. Consider the strange bedfellows on Vietnam: liberals like Henry “Scoop” Jackson joined with conservative realists like Richard Nixon in favor of the war, while opposites like George McGovern and George F. Kennan made common cause against it. In a later example of division within the club, the New York Times op-ed page of September 26, 2002, featured dueling realists: on one side of the page a manifesto by thirty-three scholars (myself included), mostly realists, opposing the coming assault on Iraq, and on the other, an essay by Kenneth Pollack asserting the urgent need to launch it.

Realists agree that power is what drives international politics, but they disagree about exactly when and where it should be unleashed or husbanded. Nor do they agree about what international distribution of power best preserves peace and stability—multipolarity (favored by most traditional realists), bipolarity (Kenneth Waltz and John J. Mearsheimer), or unipolarity (Geoffrey Blainey, Robert Gilpin, William Wohlforth). If realists expect statesmen to respect their wisdom when confronting crises today, they should explain why their advice on specific matters of war and peace varies so much despite agreement on the principles by which strategic decisions should be made. The reason for variation in practice is uncertainty in assessments of actual threats being confronted—disagreement about how to interpret evidence of the nature and extent of a given adversary’s intentions and capabilities.

REALISTS DO agree among themselves about morality. Contrary to popular belief, they are not amoral. Realism is grounded firmly in consequentialist morality, or a materialist version of situational ethics. It simply sees the probable balance of costs and benefits in the outcome of a contest, rather than the justness of either contestant’s claims going in, as the proper moral basis for action. Realists focus more on results than on motives and are more attuned to how often good motives can produce tragic results. Idealists tend to leap to support the righteous and fight the villainous when a conflict begins because they believe they are doing what is right. Right and might, however, are not always aligned, and the practical choice available in a given conflict is often between greater and lesser evils. In that case, realists are willing to accede to odious forces if doing so results in the lesser evil.

Related to this consequentialist morality is a more equivocal view of good and evil in international politics. Critics charge realists with promoting “moral equivalence.” That is not true. To be sure, realists do empathize, if not sympathize, with the motives of their opponents. The alternative is to demonize them, which can impede peaceful compromise. Sometimes, however, enemies really are demons, and when realists fail to recognize this they go badly astray, as at Munich.

The focus on outcomes brings up another big concern for realists: the balance of power. No matter whether it is ideals or interests that drive conflict, in a world without world government, power is the ultima ratio in deciding whose claim prevails. This makes realists pay special attention to how military power should be fielded and managed to influence an adversary’s behavior. They focus on calculations of what quantity, quality and types of forces are needed to win if the conflict falls into war, and, accordingly, what forces need to be kept ready in peacetime to deter the adversary from starting the war. (Kennan, who had a tin ear for military concerns, was an exception.) Liberal idealists do not deny the importance of military power, but they usually have little to say about it. They rarely provide more than vague estimates of what success will require if it comes to combat. Neoconservative idealists do pay attention to technical military issues. They are more forthrightly willing than liberals to pay high costs in blood and treasure—and usually willing to pay more than realists—for the benefits at stake. (Consider the number that remain unrepentant about Iraq.)

At the risk of overgeneralizing, one can say that idealists worry most about courage, realists about constraints; idealists focus on the benefits of resisting evil with force, realists on the costs; idealists worry more about the costs of failing to act, realists more about the costs of acting and failing; idealists are optimists, realists pessimists.

Of course, such fast and loose generalizations are dubious, if only because there is no consensus on what defines realist or idealist, or who qualifies as either one. Many critics of realism also deny that their criticism is idealistic. (Idealism is still useful as a descriptor because it highlights the salience of absolute values—whether religious, liberal, Marxist, fascist, monarchist or other—as grounds for action without reference to careful analysis of potential consequences.) Nevertheless, the generalizations ring true to most who consider themselves realists. If realists share such priorities, why then do they vary widely in their willingness to go to war?

REALISTS ARE hawks when they see an adversary as a deliberate, implacable, risk-prone aggressor bound to strike if not deterred or defeated by a formidable counterthreat. The perfect example of this is Nazi Germany—but only as the Western understanding of it solidified after 1938. Realists are doves when they believe the adversary has limited ambitions that can be accommodated or contained at moderate cost. This was the view of many about Germany prior to the Munich agreement. Until the eve of war, too many realists, like others who thought Winston Churchill alarmist, found excuses for Adolf Hitler’s demands and rationales for compromising with him. As the Munich crisis unfolded Sir Neville Henderson, the British ambassador in Berlin, wrote back to the Foreign Office: “One must also try to understand the German point of view. If we were in Germany’s place what would we, in the midst of all this war psychosis, be doing: exactly what I think the Germans are today doing.” It is a discomfiting irony that one of the most arresting expositions of realism ever written, E. H. Carr’s The Twenty Years’ Crisis, was an implicit brief for appeasement when it went to press shortly before the war.

Chamberlain’s approach was the path of least resistance, in a nation buffeted by memories of the Great War. Hindsight at the time suggested that the catastrophe of World War I might have been avoided if statesmen had shown more empathy for their adversaries, more willingness to take risks for peace and, above all, more military restraint as the summer crisis of 1914 worsened. Chamberlain and company avoided the fateful mistake of 1914 only to commit the opposite one.

As 1938 exemplifies the image of misreading pure aggression, 1914 exemplifies the image of the “security dilemma.” This concept, formulated by John Herz and further developed by Robert Jervis and others, is the tragic view of international conflict. It assumes that countries are usually opportunistic but averse to paying the high cost of war to make gains, yet cannot trust that their opponents’ aims are similarly limited. So both sides arm to deter or defend, but see each other’s precautionary mobilization as preparation to attack. Acting to maximize one’s own security threatens the opponent’s security. Neither may want war, but they may stumble into it out of misperception, miscalculation and fear of losing if they fail to strike first. In short, if the security dilemma is the real threat, then restraint rather than provocative military action should be the default option.

The challenge of crisis management since the first half of the twentieth century has essentially been to balance the risks in these competing images of threat. Hawks attend too much to the danger of unprovoked aggression, doves too much to the danger of misperception and inadvertent escalation between innocent parties. John F. Kennedy provided a solid example of balancing the contrasting risks in his handling of the Cuban missile crisis, coercing Nikita Khrushchev forcefully but holding back from precipitous action at crucial points and making limited concessions to salve Soviet pride. (Kennedy had recently read Barbara Tuchman’s The Guns of August, and he told his brother at the height of the crisis, “I am not going to follow a course which will allow anyone to write a comparable book about this time, The Missiles of October.”)

Deciding whether the greater danger is unprovoked aggression or accidental war in any given situation is about judging enemy motives, intentions, reactions and decisions. On dealing with enemy power, however, realists unite. Whether in a security dilemma or not, realists do not voluntarily accept vulnerability. They favor making whatever alliances are potent enough to assure deterrence or defeat of the enemy—and this is where they part company with those who condition action on moral and legal norms. Consider two examples in 1939 of faltering in power politics.

The realist solution that should have been pursued before the Munich crisis if Hitler’s unlimited ambitions had been appreciated, and at the least should have been undertaken in the months between Germany’s absorption of Czechoslovakia and August 1939, would have been an alliance of the Western democracies with the Soviet Union to outweigh Germany. That combination would have been problematic on both practical and moral grounds, and it is useful to remember that until World War II unfolded the record of Stalin’s regime was even more murderous than Hitler’s. But such an alliance might have averted the greatest man-made catastrophe in history. The three countries considered it, but when the French and British hesitated, the surprise Nazi-Soviet nonaggression pact took away that option. Only Hitler’s greatest miscalculation, attacking the USSR two years later, brought it about and enabled the defeat of Nazism—but now at an astronomically higher price.

In the interim, however, the democracies narrowly avoided a moral but suicidal urge to wage war against Moscow. When the Soviets invaded Finland shortly after they divided Poland with Germany, the British and French supported Moscow’s expulsion from the League of Nations and would have come to Finland’s aid militarily if they had not failed to get permission for their troops to pass through Norway and Sweden. Imagination reels at the thought of what would have happened had Britain and France put themselves at war with Germany and the Soviet Union at the same time. The motive was lofty, the potential consequences disastrous. Hans Morgenthau used this example in his classic Politics Among Nations to epitomize the foolishness of letting legal principles obscure the strategic imperatives imposed by the balance of power.

Who were the realists and idealists in all of this? Were the opponents of appeasement idealists? Neoconservatives today lay claim to Churchill as a model to be held up in opposition to today’s realists, whom they see as wimps on Iran and craven in their unwillingness to act against evil in Syria and Ukraine. Yet Kenneth Thompson, soulmate of Morgenthau, could write a whole book, Winston Churchill’s World View, interpreting Churchill as a consummate realist. Churchill and Chamberlain may have been equally realist in philosophical disposition, but they diagnosed the threat differently. Or were Chamberlain and company idealists in contemplating coming to the aid of Finland, and Churchill idealist in determining not to sue for peace after the fall of France, when Britain stood alone with no apparent prospects for winning at the time? Looking for lessons to apply to the present, two points stand out. First, trying to pigeonhole real-world statesmen as realist or not is pointless. Second, what can divide either realists or idealists, and cause coalitions across the theoretical divide, is their judgment about the severity of the threat in question—that is, their estimates of the consequences of opposed options.

WHEN RUSSIAN intervention stopped the advance of Ukrainian government forces against separatist rebels in 2014, many liberals in the West campaigned to give much heftier military aid to Kiev than the limited training and “nonlethal” supplies their countries had provided thus far. What could be wrong with helping victims repel aggressors? The realist counterargument begins by downplaying the question of which side deserves support according to standards of justice. Instead, it focuses on the questions of what will in fact happen if the West gives a big boost to Kiev’s military forces, and whether the main risk in the Ukraine conflict is more akin to 1914 or 1938.

If Russia threatened to conquer all of Ukraine, then there would be nothing to lose in supplying arms to Kiev. However, Moscow has refrained from conquering as much of Ukraine as it could have, and instead has established a stalemate over the limited separatist enclave. Is it likely that Moscow will allow its separatist clients to be defeated if the Ukrainian army is made stronger? Will Moscow allow Russian supporting forces to be driven out of eastern Ukraine? Will Moscow shrink from doing whatever is necessary to preserve the enclave, as it preserved the secession of South Ossetia and Abkhazia in its little war with Georgia? The answer to all of these questions is no, and in any contest of military escalation between Ukraine and Russia, Moscow is bound to prevail.

If the result of stronger military assistance to the morally right side (Kiev) is more intense combat, higher casualties and more destruction, but without victory, it will count as pointless suffering. And is it any likelier that stronger Ukrainian military action will defeat the rebels and Russians than that such action will drive the Russians to strike back harder and expand the area under rebel control, creating a “land bridge” to Crimea? In either case, the result would be worse than the episodic limited combat of 2015. (Realists also see more ambiguity about the current Kiev government’s claim to legal right, since it came to power through a coup or revolution—take your pick—against elected president Viktor Yanukovych.)

It may be too late to reverse the separation of the eastern Ukrainian enclave, as it is probably too late to reverse the loss of Crimea. If not, most realists would say that unless NATO goes to war against Russia to restore Ukraine’s integrity—an option out of the question in the West—the only hope for a settlement is a negotiated compromise that links reintegration of the enclave in Ukraine to recognition of Russian interests in the country. As even many liberals have accepted, this would involve ample autonomy for eastern Ukraine, agreement to refrain from integrating the country as a whole into the West via institutions such as NATO or the EU, and symbolic internal status such as recognition of Russian as a second national language—all of which amounts in effect to a “sphere of influence” for Russia. This would be a defeat for Kiev but a smaller one than consolidation of outright secession by the separatist region would be. The idea of a sphere of influence is repugnant to liberal moral principles but has been a recognized prerogative of great powers historically. It is also one the United States has taken for granted in its own hemisphere.

Ukraine’s neutralization would amount to what was once called “Finlandization” during the Cold War. Finlandization was a pejorative term. Realists, however, would see it as quite a good deal considering the alternative. Finland accepted a loss of independence in foreign policy but retained independence in its domestic political order, remaining a robust democracy. And what was the alternative? In fact, it was remarkable that Finland avoided what happened to Poland, Hungary, Czechoslovakia and the Eastern European countries corralled into the Communist camp, considering that the Finns had fought alongside Germany against the Soviet Union—but having the realistic good sense to make peace in 1944 rather than fighting to the end. In comparison with the fate of Eastern Europe, Finlandization was an impressive success for Finland.

Then there is Syria. It presents an even more forbidding set of complications and choices. There is consensus in the West that the Assad regime must be overthrown because it is murderous. And since its radical Islamist opponents are also frightening, the pressure has grown to provide aid to the “moderate” opponents of the government, those associated with the Free Syrian Army. As long as the target is the Assad regime, however, aid to the moderate opposition is less likely to end in replacing the regime with a better one than it is to empower elements worse than Bashar al-Assad.

The moderate opposition may be the right side in Syria, but that is less relevant than who is the main enemy. Is it Assad or is it the radical opposition factions such as the Islamic State, Al Qaeda or the Nusra Front? For too many of the Sunni Arab governments, the answer seems to be Assad. For the West, however, the answer should be all or any of the radical opposition. Paradoxically, supporting the moderate opposition closest to the West does not necessarily work against these main enemies. The radical groups fight among themselves, but if Assad falls, what will replace his regime? It is hardly likely that it will be the moderates, by all accounts the weakest of all the factions. If the West helps the moderates, their strengthened hand may tip the balance of power against Assad and contribute to his overthrow. In the aftermath, however, the moderates are almost certain to be shoved aside by the stronger radicals. If the Nusra Front—or, worse, the Islamic State—ends up in power in Damascus, the assistance to the moderates in the campaign against Assad will in effect have been help to the radicals. The sensible line for the West would be to aid in toppling Assad only after the radical jihadists have been eliminated—something unlikely to be accomplished.

THE IDEA of deliberately helping the Assad regime survive is more than most decent people can stomach, even if it is the lesser evil. If the option of supporting Assad’s government is out, yet helping the worse evil indirectly by strengthening the moderate rebels fighting Assad should also be out, realist policy in this case should be to avoid military engagement altogether except for whatever can do direct damage to the Islamic State and Al Qaeda.

For Ukraine, seeking negotiated neutralization and regional autonomy in the eastern area as the price for Russian withdrawal should be easier for decent people to stomach, even if it means accepting the Russian reincorporation of Crimea. Some overwrought antirealists see compromise on Ukraine as no less than another Munich. Eliot Cohen breathlessly described the situation as

a foundational crisis in an early stage whose potential for menace is as great as the crises that enveloped our civilization in the century past...when the high civilization of the West trembled before the onslaught of totalitarian enemies....We are in some ways beyond the level of danger of most of the Cold War crises.

Ukraine was, he declared, a “manifestation of something more deeply gone wrong in the West.” If Vladimir Putin is a budding Hitler, Cohen could be right. Otherwise, the best bet is that the risks and mistakes of 1914 are a better guide than those of 1938.

If negotiation does not work to defuse the Ukraine crisis, the new little cold war will fester. If so, realists will emphasize how much better the West’s position is this time around. The newly ornery Russia has indeed recovered from its prostrate status after the Cold War, and has rejuvenated some of its military capability while NATO’s atrophied a bit. Russia is still far weaker in the overall balance of power, however, than the old Soviet Union was.

The danger lies in the particular new military vulnerability NATO created for itself when it rejected realist arguments against expansion and admitted the Baltic countries into the alliance despite the technical difficulty of defending them in the event of war. While most realists opposed NATO expansion from the beginning, there is no definite realist position on how to deal with the problem now, since the addition of these members in the east is a fait accompli. Those most worried about the security dilemma will oppose provoking Moscow again by deploying allied military forces forward in the Baltics and triggering an escalating series of military reactions. Other realists, however, could worry that inflamed Russian nationalism and the continuing urge to reverse the long post–Cold War period of humiliation could make Moscow’s ambitions grow if its muscle flexing in Georgia, Crimea and eastern Ukraine succeeds. Indeed, Putin might double down if he fastens onto polls showing that Western publics oppose honoring NATO’s Article 5 commitment to defend the Baltics. Disorder in, say, Estonia could look to him like an opportunity to expose NATO as a paper tiger and break it. These realists would see the threat as Russian aggression no less than the security dilemma, and military reinforcement of the Baltics with allied NATO forces as a necessary deterrent.

Realists may disagree on how to combine accommodation and deterrence in Europe now, but they all have to place a high premium on walking back the new cold war there. Otherwise, the odds of a more established Sino-Russian alliance grow, and the balance of power is always the highest-priority concern of realists of all stripes. The rise of China is ultimately a more serious security challenge than Russian reassertion, and a united front of those two adversaries would weaken the West. In the 1970s, realists welcomed American rapprochement with Mao Zedong’s China because it weakened the more formidable adversary, the Soviet Union. Today, the relative power positions of Russia and China are reversed, so realists should hope for a way to achieve a U.S. rapprochement with Russia.

That concern for improving the balance of power does not answer the question of whether realists should recommend accommodation with China, recognizing an expanding sphere of influence as the country approaches superpower status, or containment and deterrence, seeking to keep China from dominating East Asia and controlling a greater share of world order. If the question is the same as for Russia, accommodation—or appeasement, to critics—would seem to be the answer. But the question is not the same. The argument against NATO expansion after the Cold War was that Russia was drastically weakened, had capitulated to the West and no longer needed to be deterred, and should not be kicked when it was down since it would eventually reenter the ranks of major powers. The argument today for combining accommodation on Ukraine and reinforced deterrence in the Baltic region is that Russia is still weak in the overall power balance, but should not be allowed to miscalculate the West’s resolve to honor its new alliance commitments, even if making the commitments was a mistake. In contrast, China is strong now, getting stronger and showing that its ambitions are growing in tandem with its power.

There is no realist catechism to dictate choices between compromise and containment in any of these cases unless evidence of aggressive military intent becomes unambiguous. This is unfortunate, especially in regard to the principal challenge, China, since realists do not offer a corporate alternative to policies endorsed by liberals or neoconservatives. A clearer majority of realists tilt in favor of restraint in regard to Iran, since it is a respectable middle power but not a major one, has no military allies of consequence, has not evinced suicidal behavior so far, faces an overwhelming imbalance of capability and is unlikely to think that it could get away with overt military aggression at an acceptable price. What separates these realists from more confrontational critics is a clearer focus on the high costs to our own side of the alternative to restraint, containment and deterrence of a nuclearized Iran: preventive war. There is barely any disagreement of significance among realists, or between them and any other strategic clique, about how to handle the greater threat of North Korea, an unambiguously aggressive regime against which strong deterrence has been institutionalized over more than six decades.

So there is little point in any effort to pose realism as a coherent prescription for specific choices today as long as judgments about the nature and intensity of adversary intentions vary. There will always be a point, however, in reminding policy makers to apply two realist principles to their analyses as they decide: focus not on acting against evil, but on which options will result in the least evil outcomes; and choose options supportable by the power at hand, not ones whose success requires adversaries to capitulate because they realize they are in the wrong.

The weakness of liberal and neoconservative criticisms of realism is the conceit that their ideals—Western ideals—are the only ideals that can appeal to serious people. As E. H. Carr put it:

The neoliberal argument of the harmony of interests...identifies the good of the whole with the security of those in possession. When Woodrow Wilson declared that American principles were the principles of mankind or Professor Toynbee that the security of the British Empire was “the supreme interest of the whole world,” they were in effect making the same claim made by Hitler that their countrymen are “the bearers of a higher ethic.” The worst ideals can prove as potent a motivator as the best. That grim reality is why realists recommend humility rather than hubris, and empathize with adversaries even if that sometimes risks mistakes as bad as those of their critics.

Richard K. Betts is director of the Saltzman Institute of War and Peace Studies at Columbia University, adjunct senior fellow at the Council on Foreign Relations, and author of American Force: Dangers, Delusions, and Dilemmas in National Security (Columbia University Press, 2012).

Image: Flickr/adam*b