The strong do what they can and the weak suffer what they must.
Stripped from the Melian Dialogue and reduced to the slogan “might is right”, Thucydides’ most famous line now serves as an all-purpose invocation for anyone wishing to sound hard-headed about power. The uses vary. Sometimes it appears as a harsh truth one must reconcile oneself with; sometimes as triumphalist celebration: the strong need no justification, their power is its own warrant. To this formula is attached another much-abused term: Realpolitik. Thucydides is held to be its father, Bismarck its purest embodiment, Kissinger its greatest deliberate practitioner. A line of amorality and pure power politics would thus lead straight from Thucydides, through Machiavelli, Hobbes, Schmitt, and finally to whoever feels the need to sound serious about power. This concept, coupled with the prescriptively understood “might is right”, has been invoked by the defenders of Greenland’s annexation. A closer look at both Thucydides and “Realpolitik,” as it was originally conceived, should dispel these illusions—and clarify what genuine analysis of the Greenland question would require.
The Melian Dialogue is placed in the middle of Thucydides’ History, right before the Sicilian expedition. Melos was a small island, a Spartan colony that had remained neutral throughout the war. Athens demanded submission and tribute, and the Melians refused, hoping Sparta or the gods would intervene, hoping that appeals to justice would sway the Athenians. The quote about the strong and the weak takes place during the negotiation that preceded the siege. The Melians refused to submit; Athens took the city, and the men were executed and the women and children enslaved, though this took place months later and almost certainly under different commanders. What did the Athenians actually mean by it?
The full passage, in Hornblower’s translation, is more nuanced than the slogan suggests:
We both know that in the discussion of human affairs, justice enters only when there is a corresponding power to enforce it; but the powerful exact what they can, and the weak have to comply.
This is often taken as a universal maxim or prescriptive doctrine, a theory of justice in which might confers right. Callicles in the Gorgias provides the clearest example of such a view: the strong possess a natural right to dominate, and conventional justice is merely the resentful invention of the weak.
But the Athenians at Melos make no such argument. Theirs is simply a statement of fact. A reading truer to Thucydides treats the line as descriptive. He provides an account of how human affairs work—and not how they ought to work. A philological analysis supports this: the μέν-δέ parallel construction places emphasis on the second clause, so that the point concerns what power does, not what justice permits. Against the traditional view represented by Herodotus—for whom justice, understood as the proper ordering of human affairs and cosmic balance, belongs to the gods—Thucydides makes a bold secular claim: justice concerns humans alone, and only when power is roughly equal does it enter the discussion at all.
The dialogue must also be read in its historical moment. The Athenians are not claiming that justice is always irrelevant to politics—after all, they acknowledge it “enters when there is a corresponding power to enforce it,” which implies it does enter under conditions of rough equality. Their claim is narrower: in this situation, where the power differential is so vast, appeals to justice are beside the point. And they were right, at least about Melos. The Melians’ hopes for Spartan intervention or divine rescue were illusions. Athens held overwhelming force. The outcome was never in doubt.
But sixteen years into the war, the Athenians were speaking from within a general moral erosion—the same decay Thucydides dramatized in his account of the plague, when norms and piety collapsed under pressure. The danger of such erosion lies in that it makes a certain kind of analysis habitual, applied even where it doesn’t straightforwardly fit.
What follows in Thucydides suggests as much. The dialogue is often read as a warning about hubris, placed as it is just before the Sicilian disaster. But the expedition failed not through overreach in the simple sense. The Melian mode of thinking, confidence in the idea that overwhelming power settles the question, operated at the level of the assembly’s decision to commit. When the assembly initially voted for a smaller force, Nicias attempted to dissuade them by demanding a far larger commitment, hoping the scale would give them pause. It had the opposite effect: the assembly voted enthusiastically for the greater expedition, as if the logic of Melos could simply be scaled up. Sicily, however, was not Melos. The power differential was not overwhelming, the strategic variables were far more complex, and success depended on precisely the kinds of judgment that the Melian calculus cannot capture: local conditions, timing, the management of alliances, and above all, leadership. Nicias delayed at Catana when speed was essential; he then failed to press Athens’ initial advantages before Syracuse could organize its defense. His request for massive reinforcements, which he hoped would cause Athens to recall the expedition, backfired once again. The assembly simply sent them, doubling the eventual losses. And when Sparta sent Gylippus with reinforcements, the window for quick victory had already closed. Most fatally, when the situation finally deteriorated beyond salvaging, Nicias delayed retreat through fear of how he would be received by the Athenian assembly, and then, after a lunar eclipse, out of superstition. There is an irony here: the assembly’s confidence produced a venture that required an Alcibiades, and then the assembly removed him. What remained was a commander defined by caution, and pious fear. The mode of analysis that underwrote the commitment proved irrelevant to the conditions of success.
The harder lesson is subtler than “pride goeth before destruction”. Sicily was not Melos. Ultimately, success depended on judgment and execution. The brutal clarity that served Athens at Melos—the insistence on stripping away pretence and seeing only power—did not transfer. What we hear in the Melian Dialogue may be less timeless philosophy than the voice of a city that had grown too accustomed to a certain mode of seeing, and could no longer tell when it rightly obtained. Whether the Athenians misapplied at Syracuse the same confidence they displayed at Melos is a harder question than what I can settle here—but Thucydides, by placing the dialogue where he does, invites the question.
Armchair analysts, “geopolitical” enthusiasts, and all varieties of self-styled “realists,” “Nietzscheans,” and “immoralists” have long liked to draw on the weighty German authority of the term Realpolitik—the feeling of hard analysis, seriousness, and the stripping away of illusions that is conferred upon whoever invokes it. The term, however, has a quite different origin, and a quite different meaning.
Realpolitik was coined by Ludwig von Rochau in his 1853 treatise Foundations of Realpolitik. Rochau began his political career as a radical student participating in the failed 1833 Frankfurter Wachensturm, an attempted storming of the main guard post of the military garrison at Frankfurt. The conspirators hoped to seize the treasury of the German Confederation and spark similar revolutions across the other German states. For Rochau, the failure was a first rude awakening to the unforgiving nature of politics and the limits of idealism. He was sentenced to life in prison, served three years before escaping, and fled to Paris, where he spent the next decade working as a journalist.
In 1848, as crowds filled the streets across Europe and protests ran their course from city to city—Paris, Vienna, Berlin, Milan, Budapest—monarchs fled or capitulated and constitutions were proclaimed. The Liberal moment seemed inevitable. For a brief spring, it seemed as if the old order had simply collapsed. But the Liberals, having won in the streets, did not know what to do next. They convened assemblies and debated, they worried about legality and procedure. Most fatally, they assumed that having right on their side was sufficient. Meanwhile, the forces of the old order regrouped. Armies remained loyal to their sovereigns. The monarchs, recovering their nerve, discovered that the Liberals commanded newspapers and lecture halls. The battalions, on the other hand, were still theirs. By 1849, the restoration was complete.
Realpolitik was born from the shattering of Liberal hopes in the 1848 revolutions. Witnessing the movements sweeping across Europe but failing to enact any lasting change, Rochau was forced to grapple with the reasons the Liberals had failed. He came to the pragmatic conclusion that they had built “castles in the air.” The Liberals had thought that because they had won in the realm of ideas, and held the most “just” positions, they would win in the sphere of politics. But they had failed to apprehend that politics have a “material” base. Realpolitik, then, as historicist pragmatic political theory, rests on four interlocking assumptions:
First, the law of the strong is the determining factor in politics. Sovereignty is not a natural right—those speculations can be left to philosophers and moralizers—but a reflection of the actual balance of forces. Echoing Thucydides, this is a descriptive claim. Only power can check power. It is a pipe dream to hope that laws or constitutions alone can control the state. The Liberals had failed to integrate the forces of order on their side.
Second, a constitution must reflect the given interplay of forces within a state and their relative strengths. These social forces comprise classes, interest groups, ideas, and opinions, to name a few. The most effective form of government is one that can harness the energies of the various social forces and achieve a balance among them. The nineteenth century administrative Rechtsstaat was the concrete historical manifestation of the enduring fact of political life, the scene in which these forces played out—one that both Liberals and statesmen had fundamentally misapprehended. The more harmonious a state internally, the greater its potential magnitude. This was directed at Germany’s rulers: take into account the rising middle class and incorporate it into the state.
Third, ideas matter in politics, but their role has been misunderstood. What matters is not the inherent truth or justice of an idea—in fact the basest and most immoral ideas may be the most persuasive—but how many people hold an idea and how strongly they hold it. Statecraft cannot neglect these commonly held opinions, but must weigh their relative strengths and be ready to compromise with even the “immoral” ideas.
Fourth, modernity has changed the nature of statecraft. The Zeitgeist, or spirit of the times, has become the most important factor in determining the trajectory of a nation’s politics. The rapid spread of newspapers and literacy meant that public opinion mattered more than ever. In mid-nineteenth-century Germany, this spirit was nationalism. It could provide the glue that would reconcile the competing forces within the state.
This is a far cry from amoral power politics or political pragmatism for power’s sake. Rochau was a convinced Liberal. He thought the Liberals had simply been early—material conditions had not yet caught up with them in 1848. But their time would come.
What would Rochau make of the current moment? In January 2026, the Trump administration tested the crude version of Realpolitik in real time. Trump refused to rule out military force against a NATO ally, threatened tariffs on eight European nations unless Denmark ceded Greenland, and reportedly asked the Joint Chiefs to present invasion options. The result was a transatlantic crisis. A meagre detachment of European troops was deployed to Greenland in solidarity with Denmark, and ultimately at Davos Trump retreated to a vague “framework of a future deal.” The episode is worth examining closely, because it illustrates exactly the kinds of errors Rochau diagnosed.
The case for acquisition appeals to national interest: rising global temperatures are opening the Arctic as a high-value corridor; Russia and China are making encroachments; minerals and precious metals lie beneath the ice. Leaving aside that permafrost is incredibly expensive to drill and that the strategic conversation has increasingly shifted from mineral extraction toward Arctic corridor access and missile defense positioning, we should pause to consider the question of “interest” itself.
The prevailing pro-annexation view suffers from a cramped notion of interest. It treats interest as static and material: what can we extract through the leverage we possess? But genuine Realpolitik would begin by asking what the material base of American power actually consists of. It is not military capability alone. Economic integration and trust, rather than constraints on power, are its components, social forces in Rochau’s sense, whose relative strength determines what the state can achieve. A notion of interest that sees only extraction has already misidentified the base it depends on.
Even granting the goal of greater control over Greenland, self-interest doesn’t dictate a single course. Just as the Athenians could have chosen something other than massacre and enslavement at Melos, the possibilities concerning Greenland aren’t limited to “annex” or “do nothing.” Invoking Realpolitik to justify pure assertion presents one policy as necessary when it is actually a choice—potentially a poor one even on its own terms.
A genuine analysis would require mapping out social forces, domestic and international. What is the developmental trajectory of alliance structures, of American public opinion, of great power competition? What kind of actor is America becoming through its actions?
Jingoism isn’t the only force in American politics. Every action that pushes toward radicalism also strengthens anti-radicalism, or radicalism in the other direction. Jingoism, of course, has its constituents, but so does restraint. American business interests depend on stable trade relationships and predictable legal frameworks. The Venezuela episode is instructive. American oil companies are reluctant to operate in the face of uncertainty and possible regime instability. Seizing Maduro is evidently insufficient to ensure alignment. The underlying conditions must be favorable, or capital will not flow. Domestically, each lurch towards radicalism has the potential to generate its own counter-reaction. The Democratic coalition, while having greatly fragmented over the last decade, may seize this opportunity to coalesce again with new justifications for a sharper break with the so-called “imperialism” of the United States. An administration that alienates allies abroad may find it has also mobilized opposition at home. Rochau would ask: Can jingoism really sustain itself institutionally, or does it burn through political capital faster than it accumulates? A policy that requires the permanent suppression of countervailing domestic forces is the exact opposite of “realism” or Realpolitik. It is utopian, in the precise sense Rochau criticized.
We may accept that Greenland is of vital strategic importance. The point is that there are multiple ways of gaining control. The question was always: what approach secures American interests while preserving the broader system on which American power depends? The alternative to forcible annexation was patient integration. Greenland’s circumstances made this feasible. At roughly 56,000, the population is small. Its relationship with Denmark is already strained by desires for greater autonomy. The United States could have positioned itself as a partner in Greenlandic aspirations rather than a new colonizer. These include economic investment, infrastructure development, deepened security cooperation, preferential trade arrangements. All of these create dependence and alignment without coercion. Over a generation, such a policy could have achieved effective strategic control without triggering the alliance-wide crisis that seizure would provoke. This is, of course, a slower approach, and one that does not flatter the ego because it fails to produce a pretty map with American colors over new territory. It is, however, what actual attention to the material base of power could recommend.
The obvious objection is that great power competition and the nature of domestic American politics do not permit such gradualism; that if Arctic corridors are opening now, the United States cannot afford to wait a generation. But the slower approach preserves optionality, while seizure forecloses it. It leaves open the door for future integration, or “hard annexation”, if necessity imposes it. Seizure, by contrast, commits the United States to a posture it cannot easily reverse, triggers the alliance-wide consequences described above, and does nothing to prevent Chinese or Russian Arctic operations—it may, in fact, provide their justification.
History offers examples of such a slower approach. The deep integration of Canada into an American-led security and economic order was achieved over generations, and provided a more durable alignment than any coerced arrangement could achieve. Canada has been an effectively allied state—a vassal, depending on perspective—operating within American hegemony without formal subordination, much like the broader European order. The costs of coercion, however, compound over time. Under the Trump administration we have seen a shift from this cooperative posture towards more forceful approaches. Canada, facing tariff threats and annexation rhetoric from its southern neighbor, has begun moving toward deeper integration with China—though the structural asymmetry is telling: Carney can make pretty speeches and invoke Thucydides, and middle powers can gesture toward diversification, but the gesture itself is constrained by the very dependence it seeks to escape. That Carney quickly walked back the scope of this partnership after Trump threatened 100% tariffs on Canadian goods says it all.
The partial de-escalation at Davos tilts the scales towards a slower integration with Greenland, but arriving there via a transatlantic crisis is not the same as arriving there by design. The costs of beginning from coercion rather than integration are not recovered by belatedly discovering that integration was necessary all along.
The current invocation of Realpolitik misses what actually sustains American power. Dollar hegemony rests on an alliance system in which partners choose to operate within American-led institutions because the security guarantee makes it rational . Break the guarantee, and the logic sustaining the system fractures with it. Forcibly annexing territory from an ally’s commonwealth, beyond damaging one relationship, signals to every other ally that they too might be coerced, that American protection is no longer an asset but has become a potential vulnerability. The rational response is diversification into euros, gold, into independent security arrangements, and into hedging strategies that loosen dependence on Washington. The United States, after all, is not a 19th century land empire, despite what “Dissidents” may fantasize. The cost of coercion may be the foundation of American hegemony itself.
Those who think they are being hard-headed about power are actually ignoring its material base—precisely the error Rochau diagnosed in the 1848 Liberals, only inverted. Where the Liberals mistook ideas for power, assuming that justice and reason would triumph without attending to social forces, the current self-styled realists mistake military capability for the whole of power, ignoring the institutional and economic structures, and allied good-will, that make American force projectable in the first place. Rochau would ask: What are the social forces sustaining American hegemony? What happens to them under different policy choices? The current approach sidesteps these questions and treats American power as a brute fact to be wielded. Rochau wrote against precisely this: the fantasy that power can be wielded without conditions.
There is a serious case for American retrenchment. Overextension guarantees eventual failure, and perhaps the costs of hegemony now exceed its benefits. But if retrenchment is the goal, it requires more attention to the material base of power, not less. Managed isolationism demands understanding which relationships are necessary and which are dispensable; which concessions strengthen a new equilibrium and which invite defections. The current approach does none of this.
Both Thucydides and Rochau, then, offer something more subtle than their invocations suggest. Thucydides provides a holistic understanding of human nature through war, and ultimately an anatomy of power: its strength and its limits. Rochau presents a historically minded and sociologically attuned political pragmatism in service of ideals; after all, action is future oriented, and any desired future state is, in some sense, “idealistic”. Both demand that we ask “what sustains our capacity to get what we want?” Those who invoke these thinkers as cover for crude assertion have not read them carefully. The strong do what they can—but what they can do depends on conditions they do not fully control, and which their own actions may erode.
