PRESIDENT TRUMP, unlike his predecessor, does not consider nuance a virtue. He is unlikely to appear at a Nobel Peace Prize ceremony anytime soon; we will not be treated to his reflections on the theology of St. Thomas Aquinas or Reinhold Niebuhr. Trump’s foreign policy has yet to crystallize into anything resembling a doctrine. It might be said that doctrines are overrated, of course. Frequently, they amount to post facto rationalizations for actions taken over the course of one or two presidential terms. The “Obama doctrine” came late in the day, as the former president entered his penultimate year in office. The “Reagan doctrine” only took shape from 1985, and even then its meaning was fiercely contested among those who styled themselves as its disciples. In the United Kingdom, Prime Minister Theresa May insists that political doctrines are largely the invention of an excitable commentariat too eager to intellectualize the business of politics. “There is no Mayism,” she informed the gathered media coldly as the 2017 British general-election campaign got underway, attempting to pop metaphorical balloons at the launch of her party’s manifesto.

This presents a particular problem for academics and scholars of international affairs, who are trained to believe that foreign-policy predilections exist, more or less, within predetermined paradigms. That Trump emerged from a world in which no such schools of thought prevailed means that putting a name on Trumpism can be a vexatious task. In their book on Trump’s attitude to international affairs, Brendan Simms and Charlie Laderman observe that there is more consistency in Trump’s worldview than is often presumed, and that his campaign pronouncements were in keeping with these preexisting views. But even then, it is a worldview composed of instincts rather than policy prescriptions. There was no grand strategic statement of intent from a cohort of key advisers in Foreign Affairs or the National Interest at the outset of the campaign. Foreign observers were left searching for fragments of evidence to help them piece together a picture of what might come next.

After victory, it was personalities rather than principles that received the most attention. The process of assembling the president’s national-security team began with auditions in Trump Tower or over dinner in Manhattan. We know—and we can see in the form of Secretary of State Rex Tillerson—that Trump sees merit in business acumen. Generals, from James Mattis to H. R. McMaster, are also deemed to bring something useful, and now that Steve Bannon has left the White House, they face less internal opposition. But even then, it is has been hard to discern a clear strategic script. Unpredictability is something that the new president seems to relish. He is not the first to attempt to make a virtue of this. President Nixon road tested the “madman theory” in his dealings with the Soviet Union, and Niccolò Machiavelli suggested that, in some circumstances, it was wise for a leader to “simulate madness” to keep his rivals and enemies guessing.

Once the Trump administration’s foreign policy has been through a succession of tests, of course, it may assume a more tangible form, or at least begin to follow a pattern. Should this happen, eager scholars will rush forward to give it a name or place it somewhere along a well-established continuum of realist versus liberal, isolationist versus internationalist or offshore balancer versus interventionist. In the meantime, it is perhaps too easy to get carried away with the idea that we are in uncharted territory, somehow without historical precedent.

Notwithstanding the lack of a doctrine, one thing we have learned already is that Trump operates within certain parameters in international affairs. The president may not do nuance, but he is more beholden to some norms than might have previously been assumed. He has “red lines” too, as his actions over Syria and North Korea seem to demonstrate. It is true that Trump has shown no interest in what Hal Brands calls the “intellectual architecture” of American grand strategy. More than that, a number of his key advisers have declared their hostility to some of the presuppositions that underlay the whole idea of the “liberal international order” as the leitmotif of America’s approach to the world. But even if the script has been scrapped, the White House continues to assume that there are certain rules of the game involving prestige, power and even ethics.

WHAT SETS the bounds of action, then? For Trump, it seemed to be an instinctive response in April 2017, following the latest chemical-weapons attack by the Assad regime in Syria, to order missile strikes on Shayrat Air Base, from where the attack had been launched. Those who objected that the measure was merely symbolic—not part of a carefully designed strategic plan—were at once correct and missing the point. What is more, the action in Syria became a curtain raiser of sorts: a prelude to proactive behavior in other theaters, where rogue regimes were warned that certain red lines did still exist, and the United States was willing to take action to enforce them. Soon after, a decision was apparently taken to reroute the U.S. aircraft carrier strike group Carl Vinson towards the Korean Peninsula after Pyongyang’s ballistic-missile test, also in April. Within days came the dropping of the GBU-43/B Massive Ordnance Air Blast (so-called “Mother of All Bombs”) on an ISIS affiliate in eastern Afghanistan.

There was no grand strategic master plan here in these episodic, uncoordinated and unplanned displays of U.S. military power. Nonetheless, the White House was eager to extract political capital from its actions. Thus, Trump pointedly delivered news of the missile strike in Syria to his Chinese counterpart, Xi Jinping, over chocolate cake, during dinner at Mar-a-Lago. This was intended to be a reminder of U.S. military prowess and political will. For a domestic audience, too, the president was eager to draw a distinction between himself and President Obama, on strategic and ethical grounds. On the one hand, he made clear that he was willing to tread where Obama had not. The desire to draw this contrast explains his condemnation of the Assad regime for crossing “many, many lines, beyond a red line.” On the other hand, he described the attack as nothing short of an “affront to humanity,” requiring a response on moral grounds. It was left to Secretary Tillerson to elaborate on this redrawing of red lines:

“Well, I think the message that any nation can take is, ‘If you violate international norms, if you violate international agreements, if you fail to live up to commitments, if you become a threat to others, at some point a response is likely to be undertaken.’”

Those given the task of explaining U.S. national security were quick to draw attention to the fact that these actions, from Syria to Afghanistan and North Korea, came in quick succession. Visiting Seoul on a reassurance mission shortly after the two strikes, Vice President Mike Pence asserted that “the world witnessed the strength and resolve of our new president in actions taken in Syria and Afghanistan.” The regime in Pyongyang, he warned, “would do well not to test his resolve or the strength of the armed forces of the United States in this region.”

In times past, the use of limited force—and the threat of using more—to reinforce boundaries might have been construed as a species of deterrence. Yet, for the many critics of the administration, the willingness to declare an end to the era of “strategic patience” in dealing with Pyongyang—and the concomitant game of brinkmanship—risked undermining the type of long-term credibility on which successful deterrence depends. Just what type of foreign policy, then, were we witnessing?

IN RESPONSE to these concerns, it fell to the redoubtable McMaster to find the words to rationalize the new approach. The deployment of the aircraft-carrier strike group to the East China Sea, he explained to Fox News, in his first extensive interview after becoming the president’s national security advisor, was “prudent.”

Absent any coherent alternative, this idea of “prudence” soon caught on. Cdr. Dave Benham, spokesman at U.S. Pacific Command, clarified the picture in similar terms: “The U.S. Pacific Command ordered the Carl Vinson strike group north as a prudent measure to maintain readiness and presence in the Western Pacific.” Should we be in any doubt, Secretary Mattis further elucidated, “She’s stationed in the Western Pacific for a reason. She operates freely up and down the Pacific and she’s just on her way up there because that’s where we thought it was most prudent to have her at this time.”

When one digs a little deeper under the surface, one finds that prudence keeps popping up. Within the Trump national-security team, it is not just the so-called warrior-monks who are fond of the term. Michael Anton, director of strategic communications at the National Security Council, who has so far survived the cull of Bannonites, has also deployed it on a number of occasions since the inauguration. Acknowledging that military action against North Korea was unlikely, and would have dire consequences, he told Politico, “For reasons of prudence, it can’t be taken off the table at a juncture like this.”

When it comes to the use of prudence, in fact, Anton, one of the original palace intellectuals of the Trump transition, has been here before. In his view, it is one of a number of principles of classical statecraft that should be invoked to help America set itself back on the right track in foreign affairs. In an essay for American Affairs written before he was appointed to the administration, Anton offered a strongly worded critique of what he saw as the Washington national-security establishment’s unthinking fidelity to the idea of “liberal international order.” Rather than retreat into isolationism, however, Anton expressed the belief that powerful nations, such as the United States, had to strike a balance between “contempt” and “prestige.” Being held in contempt damaged a nation’s ability to influence others, and the only antidote was to be respected or “even a little bit feared.” Striking this delicate balance was the clue to a successful foreign policy, he argued, “which means prudence is always required.”

Unlikely as it may sound, then, “prudence” is circulating as a working concept among the various foreign-policy groupings within the Trump White House. Does this mean that we are witnessing the green shoots of a new consensus where there was once civil war? Might a commitment to prudence as an operating principle offer the Trump administration the coherence many fear it lacks, or the intellectual basis for the next National Security Strategy? Or, as seems more likely, will the definition of twenty-first-century prudence—of considered counsel to the Prince—remain contested terrain?

PRUDENCE ASSUMES no system, schematic or strategic script. Therein lies much of its merit. It has both classical and Christian antecedents, but it is by nature ambivalent, historically conditioned and somewhat elastic.

Nor is its exercise something that sits easily with the character of modern democracy. In Democracy in America, Alexis de Tocqueville noted that the democratic system seemed to grind against the traditional requirements of statecraft. He warned that “foreign politics demand scarcely any of those qualities which a democracy possesses; and they require, on the contrary, the perfect use of almost all those faculties in which it is deficient.” When it came to its dealings with other states, a democracy

“cannot combine its measures with secrecy, and it will not await their consequences with patience. . . . [Democratic polities] obey the impulse of passion rather than the suggestions of prudence, and . . . abandon a mature design for the gratification of a momentary caprice.”

Such fears of imprudence weighed heavily on the minds of American strategists during the Cold War. One of the greatest challenges faced by the United States was always assumed to be the management of its passions and its purse. Thus Dwight Eisenhower’s “New Look” emphasized strategic patience, cautious containment and long-term sustainability as the best means of outlasting the Soviet Union. This implied caution in fiscal, temperamental and military affairs, as a counterbalance to the irrationalism and emotionalism that led to foreign-policy misadventure.

It was in this context that Cold War prudence was often taken to denote frugality or restraint, with which it was only situationally connected. Prudence was seen as the antidote to unwieldy idealism or democratic excitability, and thus was assumed to be the handmaiden of realism writ large. Its definition was narrowed to never exceeding the pragmatic bounds set by the national interest. This was how it lived on in much academic literature on realism thereafter, notably in the work of Hans Morgenthau, who wrote that “there can be no political morality without prudence; that is, without consideration of the political consequences of seemingly moral action.” In The Tragedy of Great Power Politics, John Mearsheimer went one step further. For states in an anarchic system, “prudence dictates that they behave according to realist logic.” Understood in this way, prudential reasoning implied the tethering of ideological excess, or concomitant military overstretch.

And yet the essential point of prudence is that it rarely dictates. As is often the case, Reinhold Niebuhr provided a more nuanced perspective in his writings. He agreed that there was an important role for “prudent self-regard” in shaping nations’ foreign policy. But he also objected to what he saw among some realists as an attenuated understanding of prudence, as some sort of “procedural standard” for foreign-policy decisions—or an aide-memoire to keep the national interest paramount at all times. The real purpose of prudence was to mediate between the three other cardinal virtues—temperance, courage and justice. In many circumstances, it was true that prudential reasoning would advise self-restraint. But true prudence would also consider the demands of courage and justice. Thus, in Niebuhr’s view, “any kind of prudence which estimates common problems from the perspective of a particular interest will define the interest too narrowly.” Human beings could not escape a feeling of “loyalties and responsibilities to a wider system of values than that of the national interest—to a civilization for instance, to a system of justice, and to a community of free nations.” This broader sense of justice, Niebuhr suggested, “must prevent prudence from becoming too prudential in defining interest.” Its job was to secure some sort of equilibrium, to “safeguard against both sentimentality and moral cynicism.”

The origins of prudence can be traced to the Athenian understanding of politics, as it developed in the aftermath of defeat in the Peloponnesian Wars. Aristotle distinguished between three “virtues of thought”: episteme (scientific knowledge), techne (craft knowledge) and phronesis (prudence, or practical wisdom). As he explained in the Nicomachean Ethics, phronesis derived from experience. It was “concerned with particulars as well as universals, and particulars become known from experience.” Its main business was “to determine not ends but means to ends, i.e., what is most useful to do.” More than that, however, phronesis also demanded powers of advocacy and rhetorical skill to persuade citizens of the most expedient course of action. The Latin word prudentia is one possible translation of phronesis, and conveys its journey from Athens to Rome. For Roman political thinkers and statesmen like Cicero, concerned with the res publica (the public thing), it was the virtue most important for senators engaged in governing the civitas.

In the hands of the Christian ethicists, the Western understanding of prudence evolved further still, as a situational ethic as well as a guide to reason. For St. Thomas Aquinas,

“Rightness of choice necessarily involves two factors, namely a due end and something suitably ordained to that due end. . . . Consequently, an intellectual virtue is needed in [a man’s] reason to complement it and make it well adjusted to these things. This virtue is prudence.”

Aquinas’s Secunda Secundae of the Summa Theologica was in part devoted to finding a synthesis of classical and Christian thinking on prudence. Following Aristotle, he considered prudence a form of practical reason, based on experience and shrewdness. It was intimately concerned with euboulia (deliberating well), and synesis (judging well). Doing God’s will on earth remained the priority of a cloistered thinker like Aquinas. But he understood that political prudence also implied scenarios in which “even as false is found with true, so is evil mingled with good.” In this spirit, as the Anglo-Australian political philosopher Kenneth Minogue later observed, “prudence is a joker in the moral pack, and its business, on occasions, is to trump its fellow virtues.”

It was partly in response to the excesses of religious enthusiasm in early modern Europe that prudence moved from the domain of individual ethics to assuming a greater role in the affairs of the state. It was this that encouraged the emergence of the practice of “prudent counsel.” A wise prince would make use of experienced counselors, learned in history but promising insight into how the maxims of practical reasoning might apply to the contingent circumstances of the present. With politique raison d’état, writers and counselors as varied as Machiavelli, Jean Bodin and the Dutch humanist Justus Lipsius sought to offer more than abstract moral injunctions when it came to questions of war and governance. Instead, they offered a distinctive counsel of prudence, or practical morality. This was based on their reading of historical, usually classical precedents, informed by a neo-Stoic ataraxia that valued calmness of mind as the antidote to zealotry.

Titian’s 1565 Allegory of Time Governed by Prudence graphically captured this evolving understanding of political wisdom. The painting depicts a man with three faces: a mature adult faces the viewer, flanked on one side by the wizened profile of an old man and on the other by the callow features of a youth. Beneath the three-faced figure sits a three-faced beast—a lion facing the viewer, profiled by a wolf on one side and a dog on the other. Across the top of the painting runs the maxim EX PRAETERITO PRAESENS PRUDENTER AGIT, NI FUTUREM ACTIONEM DETURPET: “From the experience of the past, the present acts prudently, lest it spoil future actions.” The painting may be read both as a depiction of the three ages of man and, symbolically, of a wolf devouring the memory of the past, a lion depicting the fortitude necessary in the present and a dog bounding into the future. True prudence deployed the wisdom of the past as a guide to the present, with an awareness of the need to prepare for the future.

IN RECOGNIZING the many faces of knowledge and experience, prudence ground up against the rationalism associated with the later Enlightenment, which sought to apply abstract universal rules and scientific methods to the political domain. Contra rationalism, prudential skepticism stressed the role of experience, custom and tradition. It also demanded a deeper appreciation of contingency and circumstance, and the importance of self-understanding as a guide to decisionmaking.

Edmund Burke’s political writings, in particular, demonstrate the challenges of adapting prudential reasoning to the revolutionary age, when rationalist thinking was at the height of its political influence. In his 1790 Reflections on the Revolution in France, Burke considered Jacobinism and scientific theories of government an affront to the practice of prudence. “Political reasoning is a computing principle,” he wrote, “adding, subtracting, multiplying and dividing, morally and not metaphysically or mathematically, true moral denominations.”

To his critics, the ferocity of Burke’s response to the events of the French Revolution suggested that his capacity for cool-headed reasoning had deserted him. Stung by the criticism, Burke argued that some situations were grave enough to demand such bracing honesty. So he went to a familiar armory. “If the prudence of reserve and decorum dictates silence in some circumstances,” he argued with timeless logic, “in others prudence of a higher order may justify us in speaking our thoughts.”

Burke went much further than many critics of the revolution in advocating a counterrevolutionary war to restore Bourbon government in France. By 1796, his ire turned from his fellow Whigs and Francophile radicals to the government of William Pitt, when it considered a peace treaty with revolutionary France after three years of war. Once again, Burke argued that “the rules and definitions of prudence can rarely be exact; never universal.” In his view, the idea of seeking a settlement with a regime that had murdered its king was an example of “false” or “narrow” prudence. His Letters on a Regicide Peace acknowledged the gravity of the challenges confronting Pitt’s government. It was faced with waning public support for war, and lacking allies in Europe. Nonetheless, Burke bemoaned what he saw as a desperation for peace that came from a “false reptile prudence, the result not of caution but of fear,” the result of “abject distrust of ourselves” and “an extravagant admiration of the enemy.”

For Burke, there were no set rules in international politics to guide one’s action. Decisions had to be made on the basis of the situation at hand. “Matters of prudence are under the dominion of circumstances, and not of logical analogies,” he argued. “It is absurd to take it otherwise.” Among the contingent circumstances that states had to consider when choosing between peace and war was that of their existing status and prestige among their peers and competitors. He understood that small states would often be forced to compromise when presented with superior force. But a great state, like Britain, had a reputation to maintain, and an array of different enemies, which meant that overcautiousness could damage its long-term security.

In other words, prudence demanded a self-awareness about how others saw you, rather than simply restraining one’s own passions. As he explained,

“I do not deny that in small truckling states a timely compromise with power has often been the means, and the only means, of drawling out their puny existence; but a great state is too much envied, too much dreaded, to find safety in humiliation. To be secure, it must be respected. Power, and eminence, and consideration, are things not to be begged. They must be commanded: and they who supplicate for mercy from others can never hope for justice through themselves.”

Rationalist calculations would stress the costs of war and the dangers therein. A truly prudent council, he argued, should not enfeeble preexisting power.

After Burke, those who emphasized the importance of prudence in nineteenth-century British statecraft sought to use it to mediate between sentimental emotionalism creeping into foreign policy and a hyper-rationalist calculation of the commercial costs and benefits of every action. Henry Temple, Viscount Palmerston, argued that the policy of Britain—“apart from questions which involve her own particular interests, political or commercial”—should be to serve as “the champion of justice and right.” But his counsel was that it was necessary to pursue that course “with moderation and prudence, not becoming the Quixote of the world.” John Stuart Mill, in his influential 1859 essay “A Few Words on Non-Intervention,” also saw imprudence in the fetishization of self-interest in many debates on British foreign policy. He felt that it was unwise to describe one’s approach to the world in such narrowly commercial terms. As much as anything else, this was to advertise meaner motives to the world than actually guided the actions of England abroad:

“All, therefore, who either speak or act in the name of England, are bound by the strongest obligations, both of prudence and of duty, to avoid giving either of these handles for misconstruction: to put a severe restraint upon the mania of professing to act from meaner motives than those by which we are really actuated, and to beware of perversely or capriciously singling out some particular instance in which to act on a worse principle than that by which we are ordinarily guided.”

What can we salvage of these different versions of prudence for the twenty-first century? Following Aristotle, Aquinas and Burke, it is possible to distinguish between “lower” and “higher” constructions of prudence in a way that provides some useful guidance today. Lower prudence concentrates on limited goals, retraining passions and urging caution above all else. Higher prudence incorporates more ingredients of political calculation, with a place for ethics and also a higher tolerance of risk. While caution is always necessary, it should never be allowed to become an “abject distrust of ourselves.” In higher prudence, prestige cannot simply be measured by the metrics of raw military or commercial power, but by the willingness to exercise political will in specific circumstances. Respect has to be commanded rather than expected.

One can see the appeal of this idea in an era in which the president of the United States speaks of the need for his nation to “start winning again,” or regain lost prestige. Equally, however, higher prudence requires careful curation over the longer-term and does not neatly fold within a slogan. To revisit Tocqueville’s warnings about the conduct of foreign policy in democracy, it was the height of imprudence to “abandon a mature design for the gratification of a momentary caprice.”

WRITING IN February of 2017, not a month into the life of the Trump administration, David Brooks of the New York Times asked the question of his readers, “If you could give Donald Trump the gift of a single trait to help his presidency, what would it be?” Setting out to answer the question himself, Brooks described how his thoughts had first turned to prudence. “Prudence is the ability to govern oneself with the use of reason,” he explained. “It is the ability to suppress one’s impulses for the sake of long-term goals. It is the ability to see the specific circumstances in which you are placed, and to master the art of navigating within them.” In his view, “a prudent President Trump wouldn’t spend his mornings angrily tweeting out his resentments” or “spend his afternoons barking at foreign leaders and risking nuclear war.” Thus Brooks quoted the French philosopher André Comte-Sponville, who wrote that “prudence is what differentiates action from impulse and heroes from hotheads.”

The more Brooks thought about it, however, the less he wanted to hand over such a useful virtue to such dangerous hands as those of the president. Trump seemed “intent on destroying the postwar world order—building walls, offending allies and driving away the stranger and the refugee. Do I really want to make him more prudent and effective in pursuit of malicious goals?” Instead, Brooks settled upon the gift of “fraternity” to soften those jagged edges.

In the Obama administration, it was the president who set the intellectual tone of his administration’s foreign policy. It was to David Brooks, in fact, that he once revealed his fondness for the philosophy of Reinhold Niebuhr. Those looking for professorial guidance from President Trump will be disappointed. Yet one of the essential elements of historical prudence is that it puts the onus on the counselor rather than the prince. Since Trump was elected, there has been a bonfire of many of the established concepts of American grand strategy. A new language is needed to make sense of America’s place in a changing world. Status matters, but there is a fine line to tread between caution and overreach. Before the mold is reset, those seeking to advise the prince could do worse than dust of some of the classical principles of statecraft—and reach for prudence once more.

John Bew is a professor of history and foreign policy at the War Studies Department, King’s College London and research fellow at Policy Exchange. David Martin Jones is an honorary reader in the School of Political Science and International Studies at the University of Queensland and visiting professor in the War Studies Department, King’s College, London.

Image: Donald Trump attends the APEC Economic Leaders’ Meeting in Danang, Vietnam, November 11, 2017. Reuters/Jorge Silva