Cover of Henry Kissinger’s Diplomacy, used as the shared image for this summary series.
In 1994, Henry Kissinger published the book Diplomacy. He was a renowned scholar and diplomat who served as the United States National Security Advisor and Secretary of State. His book provides an extensive sweep of the history of foreign affairs and the art of diplomacy, with a particular focus on the 20th century and the Western World. Kissinger, known for his alignment with the realist school of international relations, inquires into the concepts of the balance of power, raison d'État, and Realpolitik across different eras.
His work has been widely praised for its scope and intricate detail. Yet, it has also faced criticism for its focus on individuals over structural forces, and for presenting a reductive view of history. Also, critics have also pointed out that the book focuses excessively on Kissinger's individual role in events, potentially overstating his impact. In any case, his ideas are worthy of consideration.
This article presents a summary of Kissinger's ideas in the fifth chapter of his book, called "Two Revolutionaries: Napoleon III and Bismarck".
You can find all available summaries of this book, or you can read the summary from the previous chapter of the book, by clicking these links.
The Collapse of the Metternich System
The Crimean War opened a period in which the moral and diplomatic restraints of the Vienna settlement rapidly disappeared. Between 1859 and 1870, Europe passed through four connected crises: the Franco-Piedmontese war against Austria, the conflict over Schleswig-Holstein, the Austro-Prussian War, and the Franco-Prussian War. Out of these crises came a new balance of power in which France lost its old pre-eminence and Germany became the strongest state on the Continent. More important for Kissinger, the principle that the conservative monarchies should preserve one another and settle disputes by consensus gave way to a harsher practice of power politics. The French phrase raison d’état was replaced by the German term Realpolitik, though the underlying idea remained the same: states would increasingly act according to calculations of power rather than shared legitimacy.
Napoleon III and Bismarck were unlikely collaborators in this transformation. Napoleon had been associated in youth with Italian secret societies hostile to Austrian domination, became President of France in 1848, and turned himself into Emperor in 1852 after a coup. Bismarck came from the Prussian Junker elite and opposed the liberal Revolution of 1848. He became Prussian Prime Minister in 1862 when King William I needed someone capable of forcing through army reforms against parliamentary resistance. Their origins and temperaments differed sharply, but both rejected the premises of the Vienna system. Napoleon saw it as a structure designed to isolate and restrain France. Bismarck saw it as a structure that condemned Prussia to remain Austria’s junior partner in the German Confederation.
Their achievements, however, moved in opposite directions. Napoleon believed that the dismantling of the Vienna settlement would release France from diplomatic confinement and make him the patron of European nationalism. Instead, his actions helped unify Italy and Germany. Both developments weakened France’s strategic position. He destroyed many of the inherited checks on European conflict without creating a new order favorable to French interests. By the end of his rule, France was more isolated than it had been under Metternich.
Bismarck’s result was the reverse. Before he took office, German unity was usually imagined as the work of liberal constitutional nationalism, the cause that had animated 1848. Within a few years, Bismarck made unity a product of Prussian power and war. Dynastic negotiation helped frame the outcome. His Germany was too democratic for old conservatives, too authoritarian for liberals, and too indifferent to legitimacy for traditional monarchists. It fit Bismarck’s own genius for manipulating antagonisms at home and abroad, but that dependence on one exceptional political intelligence would become one of its deepest weaknesses.
Napoleon III and the Search for Legitimacy
Napoleon III was called the “Sphinx of the Tuileries,” a label rooted in contemporaries’ habit of mistaking obscurity for depth and assuming that his policies concealed vast designs. Bismarck saw the problem more clearly: Napoleon’s intelligence, in Kissinger’s telling, was overrated, with observers underestimating his sentimentality. He possessed ambition and theatrical instinct, and he was sensitive to public opinion. What he lacked was an inner strategic compass.
His insecurity began with legitimacy. Like his uncle, Napoleon III bore a name that both attracted popular support and alarmed Europe’s legitimate monarchs. The conservative powers had reluctantly recognized republican France after 1848, wary that intervention might revive the revolutionary wars. After Napoleon’s coup and proclamation of the Second Empire, recognition again became an issue: the Vienna settlement had explicitly barred the Bonapartes from the French throne. Austria accepted the accomplished fact first, and Prussia followed. Russia remained cooler, refusing to address Napoleon as a monarchical “brother” and using the lesser language of friendship. Whether these slights were decisive in themselves mattered less than what they revealed: Napoleon was a revolutionary ruler who craved acceptance from the very dynastic order he wished to undermine.
Kissinger stresses the irony that Napoleon was more successful in domestic policy, which bored him, than in foreign policy, which fascinated him. He encouraged the credit institutions that helped industrialize France, and he empowered Baron Haussmann to transform Paris from a medieval city of narrow streets into a capital of broad boulevards, monumental buildings, and open vistas. These boulevards also made revolution harder by giving troops clearer fields of fire, but the achievement remained substantial. In foreign affairs, by contrast, Napoleon was divided between a desire for monarchical respectability and a desire to be remembered as the champion of nationality and revision.
That division shaped every major decision. He wanted to undo the territorial clauses of 1815 and reopen the map of Europe. Yet he failed to grasp that a successful attack on the Vienna system would also make German unity more likely. He supported Italian nationalism when it seemed confined to northern Italy and Polish nationalism when support carried no serious risk of war. He admired aspects of Prussia’s national character but feared the rise of a unified Germany. In each case, he encouraged forces that he later tried to restrain.
Unable to secure full legitimacy from the conservative courts he distrusted, Napoleon leaned on public opinion at home. Foreign policy became an instrument for confirming his throne and sustaining his popularity. This made him a prisoner of crises he had helped create. He repeatedly encouraged unrest or diplomatic revision, then retreated when the consequences became dangerous. The instrument that most suited him was a European congress, where he could pose as the arbiter of continental change without committing France to a clear war aim. But no other Great Power wished to attend a congress whose purpose was to revise borders for Napoleon’s benefit. As Kissinger frames the lesson, a state that seeks great changes while refusing great risks condemns itself to futility.
France after the Crimean War had two coherent strategic choices. It could follow Richelieu’s old policy by keeping Central Europe divided and sustaining the German principalities as a buffer against any consolidated power east of the Rhine. Or it could support nationalism in Germany and Italy, hoping that new national states would reward France for its sympathy. Napoleon tried to pursue both courses at once. This was especially dangerous in Germany because the German Confederation, though designed partly as a shield against France, was structurally defensive and nearly incapable of offensive action. It contained too many states, too many rivalries, and too many legal restraints to threaten France unless faced with overwhelming external danger. Napoleon saw the Confederation as a hostile relic of 1815, but the alternative was not a harmlessly fragmented Central Europe. The alternative was a unified Germany with more people and greater industrial potential than France.
Italy, Poland, and the Costs of Ambiguity
Napoleon’s first major post-Crimean move came in Italy. In July 1858, he reached a secret understanding with Camillo Benso di Cavour, the Prime Minister of Piedmont-Sardinia. France would help Piedmont fight Austria and liberate northern Italy, while Napoleon would receive Nice and Savoy. The arrangement was risky. Success would create a stronger state across one of France’s traditional invasion routes; failure would humiliate France; either outcome would alarm Europe.
Austria supplied the pretext in 1859 by allowing Piedmontese provocations to draw it into declaring war. France then treated Austria’s move as a declaration against itself. Napoleon imagined two possible outcomes. If the war went well, northern Italy would be freed from Austria and Europe might gather at a congress under French sponsorship to revise the continental settlement more broadly. If the war bogged down, he might bargain with Austria at Piedmont’s expense and obtain some advantage for France. This double calculation already showed the weakness of his method. He wanted to be both the patron of nationality and the manipulator of dynastic balance.
French victories at Magenta and Solferino brought military success but political alarm. German nationalist feeling rose against France as the smaller German states feared a new Napoleonic attack on the German world. At the same time, Napoleon was shaken by the carnage at Solferino. Without informing Piedmont, he concluded the armistice of Villafranca with Austria on July 11, 1859. The settlement satisfied neither of his purposes. Piedmont was angered: Italian nationalism had outgrown Napoleon’s limited plan for a medium-sized northern satellite. Austria remained attached to Venetia, leaving another unresolved Italian question. Britain, already suspicious, was further alienated. France gained Nice and Savoy, but the larger diplomatic result was a weakening of French influence.
The Polish revolt of 1863 deepened the pattern. Napoleon wished to revive the Bonapartist tradition of sympathy for Poland and first asked Russia to make concessions to its rebellious subjects. Russia refused even to discuss the matter. He then sought cooperation from Great Britain, but Palmerston distrusted him. Finally, Napoleon approached Austria with a fantastic plan under which Austria would surrender its Polish lands to a projected Polish state and Venetia to Italy, then compensate itself in Silesia and the Balkans. Austria had no reason to risk war with Russia and Prussia in order to create a French-aligned Poland on its frontier. The episode revealed how detached Napoleon’s schemes had become from the interests of the powers he expected to cooperate with him.
For Kissinger, these failures show the cost of policy driven by mood rather than strategy. France had historically sought influence over Germany’s internal arrangements because a divided Central Europe was the foundation of French security. Napoleon instead looked toward peripheral questions—Italy and Poland—where dramatic gestures seemed possible at lower risk. Yet as Europe’s center of gravity moved toward the German question, France found itself increasingly alone.
The German Question and the Road to 1870
The Schleswig-Holstein crisis of 1864 marked a decisive shift. The duchies were tied dynastically to Denmark but also connected to the German Confederation, creating a complicated mixture of legal, national, and dynastic claims. Its details mattered less than the diplomatic fact that Austria and Prussia jointly went to war against Denmark on behalf of a German cause. For the first time since Vienna, the two leading German powers disrupted Central Europe in offensive action against a non-German state. They detached Schleswig-Holstein from Denmark and occupied the duchies together while the rest of Europe stood aside.
Under the older system, the Great Powers would probably have convened to restore an approximation of the status quo. By 1864, that mechanism had collapsed. Russia had no wish to oppose Austria and Prussia after their restraint during the Polish revolt. Britain disliked the attack on Denmark but lacked a Continental ally. France wavered between sympathy for national claims and the traditional French need to prevent German consolidation. Napoleon’s Foreign Minister spoke of circumspection, but Kissinger treats that language as the alibi of a government unable to choose. Inaction allowed Austria and Prussia to settle the duchies. Bismarck then turned the joint victory into a trap for Austria. The two powers now had to administer territories adjacent to Prussia but far from Austria, giving Bismarck an ideal arena for confrontation.
Napoleon still admired Prussia as the most national and liberal of the German monarchies. He believed an Austro-Prussian war might serve France because he expected Austria to win and hoped to trade neutrality for compensation. In February 1866, he effectively encouraged Prussia by promising absolute neutrality. Bismarck understood that French neutrality was being offered for a price and hinted at possible French gains in Belgium or Luxembourg, promises that cost little because he had no intention of risking Prussia for Napoleon once neutrality was secured.
Napoleon’s scheme was a blurred attempt to revive Richelieu’s balancing policy. He expected Prussia to be defeated or checked. France would mediate, Venetia would go to Italy, and Germany would be reorganized into a Prussian-led north and an Austria- or France-supported south. Richelieu had judged the relation of forces and was prepared to fight for his design. Napoleon would do neither. When he proposed another European congress, Britain made attendance conditional on France accepting the status quo. That condition would have preserved the German arrangements on which French security rested. Napoleon refused, invoking national passions and risking the rise of a Germany more dangerous to France than the old Confederation.
Adolphe Thiers understood the danger. In May 1866, he warned that Prussian victory would recreate a Central European colossus, now based in Berlin rather than Vienna. France, he argued, had the right to resist in the name of the independence of the German states and the European balance. Kissinger treats Thiers’s analysis as sound but late. A determined French warning might still have restrained Bismarck. That was especially true if France declared that it would not permit Austria’s defeat or the destruction of states such as Hanover. Napoleon refused, expecting Austria to prevail and letting his hatred of the treaties of 1815 outweigh his sense of France’s enduring interest.
Prussia’s quick victory in 1866 exposed the emptiness of Napoleon’s policy. France should, by Richelieu’s logic, have helped the loser to prevent a decisive Prussian triumph. Instead, Napoleon hesitated. Bismarck let him mediate the peace, but the substance belonged to Prussia. The Treaty of Prague in August 1866 expelled Austria from German affairs. Prussia annexed Hanover, Hesse-Cassel, Schleswig-Holstein, and Frankfurt. The annexations showed that legitimacy no longer governed the European order. The remaining North German states entered the North German Confederation under Prussian control, while the South German states kept formal independence but accepted military treaties placing their armies under Prussian command in war. Germany was now one crisis away from unity.
After 1866, Napoleon tried too late to recover. Austria had no interest in helping the France that had helped drive it out of Italy and Germany. Britain was repelled by French designs on Luxembourg and Belgium. Russia had not forgiven Napoleon’s conduct over Poland. France faced the collapse of its historic pre-eminence without allies, and Napoleon sought a prestige success wherever he could find one. The Spanish succession crisis offered the final occasion. Napoleon demanded that King William of Prussia guarantee that no Hohenzollern prince would seek the vacant Spanish throne. The demand had little bearing on the real balance of power, but it could produce a public victory.
Bismarck turned the gesture against him. King William refused the French demand politely and correctly, then sent Bismarck an account of the exchange at Ems. Bismarck edited the telegram to remove the evidence of royal patience and make the exchange appear as a deliberate snub to France. By leaking the Ems Dispatch, he inflamed French public opinion and drew Napoleon into declaring war in 1870. Prussia won swiftly with the help of the other German states. On January 18, 1871, the German Empire was proclaimed in the Hall of Mirrors at Versailles. Napoleon had achieved the revolution in Europe he had sought, but its result was the opposite of his intention: France had helped destroy the old restraints and found itself facing a unified Germany.
France’s Strategic Paralysis
Kissinger’s judgment on Napoleon is severe because the Emperor’s failure was not a shortage of ideas but an inability to relate ideas to reality. He broke the Holy Alliance by exploiting the Crimean War, but he never decided what order should replace it. From 1853 to 1871, Europe moved through a period of relative chaos in which legitimacy lost its restraining force and raw power became increasingly decisive. Napoleon encouraged upheavals because he assumed that France could profit from them. He did not recognize that France lacked the power to control the nationalist forces he encouraged.
His repeated calls for European congresses expose the same weakness. He sought congresses after the Crimean War and before the Italian War. He sought them again during the Polish revolt, during the Danish War, and before the Austro-Prussian War. In each case, he hoped to gain border revisions at the conference table. He could not define them precisely and would not fight to impose them. His schemes were too radical to attract consensus and France was not strong enough to compel agreement. As a result, the country that had invented raison d’état drifted into a widening gap between its image of itself as Europe’s leading power and its actual capacity.
Kissinger extends the point beyond Napoleon’s reign. Since the Crimean War, he argues, France often sought arrangements with lesser powers willing to accept its leadership because it could not dominate alliances with Great Britain, Germany, Russia, or the United States and disliked junior status. He sees the nineteenth-century pattern in alignments with Sardinia, Romania, and middle German states. He then compares it with interwar ties to Czechoslovakia, Yugoslavia, and Romania, and later with post-de Gaulle attempts to build a European counterweight to American leadership. Napoleon III helped create a world in which France’s universal aspirations no longer matched the conditions that had once sustained French predominance.
Bismarck’s Conservative Revolution
Bismarck completed the destruction Napoleon had begun, but with a different mind and a more coherent strategy. His public identity was conservative. He opposed the liberal Revolution of 1848 and rejected parliamentary constitutionalism as the basis of German unity. Yet he later introduced universal male suffrage in the German Empire and created an unmatched social welfare system. He had rejected the Frankfurt Parliament’s offer of the imperial crown to the Prussian King in 1848, but little more than twenty years later he placed that crown on a Prussian head through war and dynastic compact.
This makes him, in Kissinger’s sense, a revolutionary in conservative clothing. Established orders are often slow to recognize mortal challenges, especially when the challenger appears to defend traditional values. The Metternich system rested on three related premises. It depended on the European balance of power, the equilibrium between Austria and Prussia within Germany, and the solidarity of the conservative courts of Prussia, Austria, and Russia. Bismarck rejected all three. He believed Prussia had become strong enough to stand without the Holy Alliance. Shared interest rather than ideology could connect Prussia to Russia. Austria was Prussia’s rival rather than its partner, and Napoleon III’s restless diplomacy was an opportunity rather than only a threat.
The difference appeared as early as Bismarck’s 1850 attack on liberal German nationalism. On the surface, he sounded like a Metternichian conservative condemning parliamentary agitation. Beneath the surface, he was asserting that Prussia could be conservative domestically. It did not have to tie itself to Austria or to any general conservative alliance. Prussia could impose its preferences in Germany by its own strength. Like Richelieu, Bismarck separated the interests of the state from universal principles, though the principles at issue were political and dynastic rather than religious.
His solution to Prussia’s exposed position in Central Europe was flexibility. Instead of clinging to the Holy Alliance, Prussia should keep relations open in every direction and remain closer to each major power than those powers were to one another. Because Prussia’s central objective was Germany, it had fewer external commitments than the other major powers. Britain had its empire and the general balance to consider. Russia had interests in Eastern Europe, Asia, and the Ottoman world. France had Italy, empire, and Mexico. Austria had Italy, the Balkans, and the German Confederation. Prussia could therefore withhold commitment and sell cooperation when circumstances became favorable.
This logic required keeping open even the French option. For Bismarck’s conservative mentors, any understanding with Napoleon III was morally repugnant because he was a Bonaparte and a symbol of revolution. Bismarck did not deny that Napoleon might be dangerous. He argued that danger and opportunity could coexist. The more Austria feared France, the more concessions Prussia might extract. Moreover, a state’s bargaining position depended on the options others believed it possessed. To announce permanent hostility to France would simplify the calculations of Prussia’s rivals and reduce Prussia’s freedom of action.
Realpolitik Against Legitimacy
The break between Bismarck and the older conservative world is clearest in his correspondence with Leopold von Gerlach. Gerlach was the Prussian royal adviser who had helped launch his career. Bismarck argued that Austria could no longer be treated as a friend unless it accepted a division of spheres in Germany. If necessary, Prussia should weaken it through diplomacy, deception, and opportunity. Gerlach answered that Prussia should restore the Holy Alliance and isolate Bonapartist France.
The argument became sharper when Bismarck proposed gestures toward Napoleon, including inviting him to observe Prussian maneuvers. Gerlach saw Napoleon as Prussia’s natural enemy and insisted that the war against revolution remained the central political principle. Bismarck’s reply shifted the issue from legitimacy to patriotism. France mattered to him only as it affected Prussia. If he were French, he could serve a Bourbon pretender. As a Prussian diplomat, his duty was to the king and country he served. Personal sympathies and antipathies toward foreign powers were not signs of moral seriousness; in foreign affairs, they could become disloyalty.
For Bismarck, Realpolitik demanded that a statesman assess every force in relation to national interest. Ideas, alliances, and regimes mattered because they shaped what states could do. Personal belief did not disappear, but it did not decide policy. Kissinger compares this to Richelieu’s distinction between private salvation and state necessity: individuals may be judged by divine standards, but mortal states are judged by whether their policies work. Bismarck therefore denied the relevance of Gerlach’s universal conservatism to Prussia’s diplomatic duty.
This outlook also marked a broader intellectual shift. The Metternich system had treated Europe as a carefully balanced mechanism in which every disturbance threatened the whole. Bismarck saw politics more like particles in motion, with forces constantly changing in relation to one another. No alliance, ideology, or alignment was permanent by nature. National interest had to be inferred from circumstances. Yet Kissinger adds an important qualification. Bismarck’s realism rested on its own unprovable faith: that a sufficiently precise analysis of circumstances would lead capable statesmen to the same conclusion. Because Bismarck was usually able to make the correct judgment, this assumption served him brilliantly. It served his successors badly.
Bismarck’s diplomatic reports developed this analysis with unusual consistency. He rejected sentimental alliances and called policy the art of the possible and the science of the relative. He also argued that even the king could not subordinate the state’s interest to personal likes or dislikes. Austria was not a conservative brother but a foreign power blocking Prussia’s natural arena in Germany. During the Crimean War and again in 1859, he urged Prussia to exploit Austria’s difficulties. What Metternich would have considered heresy, Bismarck regarded as Prussian patriotism.
His 1856 analysis after the Crimean War was especially important. He saw that Austria had broken the unity of the conservative courts by alienating Russia, and he predicted that France and Russia would naturally draw closer because they had few conflicting interests. Napoleon, needing opportunities for prestige and military action, would likely find Italy an ideal pretext against Austria. According to Bismarck, Prussia should avoid binding itself more tightly to Austria, Britain, or the German Confederation. Britain lacked the land forces to be decisive, the Confederation would not hold together under a two-front strain, and Austria had become Prussia’s main obstacle. Prussia should preserve freedom of action and reverse the habits of the Metternich period.
Triumph and the New German Problem
Once Bismarck became Prime Minister in 1862, the ideas he had developed in diplomatic memoranda became policy. Within five years, through the crises already traced, he removed Austria from Germany and destroyed France’s remaining hope that Central Europe could be managed according to Richelieu’s old formula. German unity emerged, but it did not embody the liberal and constitutional ideals of the previous generations of German nationalists. It was a compact among sovereigns, organized around Prussian power and validated by military success. Its legitimacy came less from self-determination than from the fact that Prussia had imposed the outcome.
Kissinger gives Bismarck credit for moderation after victory. He was ruthless in preparing wars but prudent in concluding them, and once he had secured the borders he considered essential, he conducted a stabilizing foreign policy for two decades. The difficulty was structural. Germany had been unified by a diplomacy that presupposed endless maneuverability, yet the very success of unification reduced maneuverability. Europe now had fewer actors, and the actors that remained were larger and more rigid. A generally acceptable balance became harder to negotiate and harder to preserve without repeated tests of strength.
The annexation of Alsace-Lorraine after the Franco-Prussian War made the problem worse. It turned French hostility into a permanent fact and destroyed the French option that Bismarck had once considered essential. In the 1850s, he had sacrificed his friendship with Gerlach to keep open the possibility of cooperation with France. After 1871, France became Germany’s irreconcilable enemy. Bismarck had warned against making hostility to France an “organic” feature of Prussian policy, but the peace settlement did exactly that.
Germany’s new strength also changed the psychology of the European balance. The old German Confederation had been clumsy, defensive, and internally divided. A united Germany under Prussian leadership was no longer a potential victim of aggression but a potential threat to the equilibrium. That transformation made a coalition of other powers against Germany conceivable. Fear of such a coalition became a recurring nightmare of German policy. Disraeli grasped the scale of the change immediately. He described the Franco-Prussian War as a German revolution that had swept away diplomatic traditions and destroyed the old balance of power.
Bismarck’s personal mastery concealed these dilemmas while he remained in office. He could manipulate commitments, fears, and rivalries with extraordinary subtlety, but his arrangements were too complex to become an institutional design. Once he was gone, successors and rivals sought security through armaments rather than diplomacy. In Kissinger’s interpretation, Bismarck’s failure to institutionalize his foreign policy put Germany on a treadmill that led first to an arms race and then to war.
The empire’s domestic structure reinforced the danger. Bismarck’s constitution gave Germany universal male suffrage, but the Reichstag did not control the government. The Emperor appointed and removed the Chancellor. Bismarck could play Emperor and Parliament off against each other as he played foreign powers against one another, but the system depended on his skill. His successors lacked his daring and judgment. The result was nationalism without democratic responsibility and democracy without real governing power.
Two Revolutionary Legacies
Kissinger ends by treating Napoleon III and Bismarck as embodiments of modern dilemmas. Napoleon represented the tendency to confuse foreign policy with public relations. He had revolutionary ideas but retreated before their consequences. Because he was insecure about his legitimacy and uncertain about his purposes, he used public opinion as a substitute for strategic conviction. He created crises to impress opinion and then found himself trapped by the pressures he had magnified. In the end, reality, not publicity, determined the outcome.
Bismarck represented the opposite tendency: the identification of policy with the analysis of power. He saw Prussia’s opportunity with great clarity and acted with the confidence Napoleon lacked. The Germany he created proved durable enough to survive defeats, occupations, and division. Yet his achievement also imposed on Germany a style of policy that required a great statesman in every generation. Such figures rarely appear. Imperial Germany’s institutions also discouraged responsible political judgment. For that reason, Bismarck planted the seeds of both German greatness and German catastrophe.
The chapter’s final judgment is symmetrical and unsparing. Napoleon left France strategically paralyzed because he sought transformations he could neither define nor control. Bismarck left Germany with greatness that its institutions and successors could not assimilate. Together, they destroyed the restraints of the Vienna system and inaugurated a Europe in which power was less restrained by legitimacy, nationalism was harder to contain, and diplomacy increasingly depended on calculations that only exceptional statesmen could manage safely.
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