The 1860s and 70s were a time of great change. National identities were in flux, many people and regions having conflicting loyalties which pulled them towards different forms of nationalism, regionalism and political ideology. This was just as true in Europe as it was in North America.
In Germany, nation unification under a liberal system had appeared in reach during the Revolutions of 1848. When the conservative Austrian chancellor Schwarzenberg rejected the idea of German unification in 1849, the Frankfurt Assembly had offered the crown to Frederick William IV, King of Prussia. The King refused to accept what he regarded as a “dog collar with which they wish to lash me to the revolution of 1848.” Hereafter, it was obvious that German unification could come about only through the machinations of either Austria or Prussia.
Austria sought to dominate the German Confederation in order protect its position as a European great power, while Prussia saw itself as the natural leader of Germany. This belief was not unreasonable, as Austria had begun to fall far behind Prussia in economic and military affairs. Even with a far smaller population, Prussia produced twice as much coal and iron ore as Austria. The crisis over Schleswig-Holstein would provide Prussian Minister-President Otto von Bismarck with an opportunity to cement Prussia’s pre-eminence over their Austrian rival.
The two Duchies of Schleswig and Holstein were autonomous states under the sovereignty of the King of Denmark. Holstein was predominantly populated by Germans, whereas Schleswig had a more mixed German-Danish population. Both were a long running cause célèbre of German nationalism. The crisis arose in March 1863 when King Frederick VII of Denmark announced a unified constitution for Schleswig and Denmark. With Britain distracted by the ongoing war in North America, Bismarck saw an opportunity to embarrass Austria in the eyes of the other German states by acting unilaterally against Denmark. While the Austrians dithered, Prussia mobilised its Army and declared war on Denmark in August 1863, beginning the Prusso-Danish War.
Despite an inconclusive naval engagement at the Battle of Heligoland and receiving military support only from the Kingdom of Hannover, Prussia ultimately defeated the Danes and secured the direct annexation of Schleswig-Holstein. The result of the war dramatically raised the prestige of Prussia, cementing it in the eyes of even of those more partial to Austria as the natural leader of Germany. Austria, on the other hand, was humiliated.
These events set the stage for the War of German Unification in 1866. Prussia’s additional prestige from the war with Denmark proved advantageous, as pressure from German nationalists (even those of a liberal, previously anti-Prussian persuasion) led many rulers otherwise tempted to side with Austria to remain neutral. Most significantly, the neutrality of the Kingdom of Hannover allowed the Prussians to concentrate the great majority of their forces against Austria. Bismarck also concluded an offensive alliance with Italy in April, with Italy wishing to the annex Italian-speaking Austrian territory in Venetia.
Prussia’s preparations for war were dealt a great blow on the 7th May by the sudden assassination of Otto von Bismarck by disillusioned anti-war student Ferdinand Cohen-Blind, who shot the Prussian Minister-President three times with a revolver. Despite this disaster, the slide towards war was already irreversible. Upon the outbreak of the war, Prussia speedily defeated the forces of the Kingdom of Saxony. Four Prussian field armies commanded by Helmuth von Molkte then advanced into Austrian Bohemia. The subsequent Battle of Sadowa decided the war, as von Molkte’s armies completely destroyed the Austrian forces. Austrian commander Ludwig von Benedek was unable to withdraw his forces across the Danube river and was left with no choice but to surrender his army.
Prussian victory at the Battle of Sadowa, the penultimate battle of the War of German Unification
This traumatic Austrian defeat led to the conclusion of the war. Whereas Bismarck had reportedly been reluctant to inflict a harsh peace on Austria, King Wilhelm of Prussia and his other ministers had no such compunctions. In a peace mediated by France, Prussia annexed Saxony as well as a few smaller central German states. Bohemia, Moravia and Austrian Silesia was separated from Austria and united as a Kingdom of Bohemia-Moravia in personal union with Prussia. Austria was also ejected from the German Confederation and was made to surrender Venetia to Italy. The acquiescence of France to these terms, which amounted to nothing less than a blueprint for German unification under Prussian leadership, was bought with the annexation of Luxembourg and the Bavarian Rhineland, as well as the surrender of the Prussian Saar region.
At this point, the only remaining impediment to full German unification was the particularism of the south German states based on their separate Catholic identity. At some points in history this separate identity had been incredibly strong and seemed an insurmountable barrier to unification, with one Catholic paper observing that there was “a vastly more profound bond between a Catholic German and a Catholic African than between the latter and a German atheist.” Nevertheless, the rise of Prussian prestige discredited these tendencies and liberal nationalists were now in ascendance across southern Germany. The accord between these liberal nationalists and Prussian conservatives in favour of unification, and a belief that with Hannover and Bohemia there could be a balance in any new German state, opened the way for a deeper German integration. This culminated in the 1868 Berlin Conference, which replaced the German Confederation with a new German Federal Empire. King Wilhelm of Prussia assumed the title of Emperor of Germany. This new entity constituted a single economic area, with a central government and unified military forces.
In Austria, which was now excluded from this process of German unification, the defeat in the war shook the very foundations of the state and led to a new constitutional settlement designed to preserve the eclectic remains of the once vast Habsburg domains. The settlement sought to reconcile with the Hungarians by reconstituting the historic Kingdom of Hungary, now the largest part of remaining Empire. In order to prevent the Hungarians from completely dominating the new state structure, self-rule was also established in the Polish-majority Kingdom of Galicia. The compromise of 1867 between the Austrians, Hungarians and Polish Galicians established the Empire of Austria-Hungary-Galicia (which became commonly known as the Triple Monarchy).
Italy had nominally been a victor in the War of German Unification, achieving the long-desired liberation of Venetia from Austrian rule and the final ejection of Austrian influence from the Italian peninsula. This acquisition, however, had been achieved more at the beneficence of Prussia than as a result of Italian military success. Additionally, Italian nationalists were dissatisfied by the failure to annex the remains of the Papal States. Such an annexation would allow the move of the capital of the Italian state to Rome and complete the process of Italian unification (Risorgimento).
French Emperor Napoleon III would continue to frustrate this desire with the stationing of French troops in Rome, a presence he felt compelled to maintain as his regime increasingly relied on the support of political Catholicism. In the long run, this would lead to a deep enmity between Italy and France. For the time being, however, Italy was far too weak to seriously challenge France. Italy was the poorest nation in western Europe, afflicted by parochialism and a strong regional inequity between the north and south of the country. From 1871, Italy was also diplomatically isolated in Europe. France, Germany and the Triple Monarchy had established the League of the Three Emperors. This was a loose alliance built more on a distrustful need to maintain a balance of power than any mutual regard between the signatories.
The New Order in Europe, 1870
In Britain, the Prime Minister Lord Palmerston had passed away near the end of 1865, just months after the Treaty of Brussels ended the war in North America that had dominated the end of his long political career. His death at the moment of his greatest triumph, having crippled the rising American threat to Britain’s imperial hegemony, elevated him above all the other British Prime Ministers of the 19th century.
His worldview, dubbed “Palmerstonianism”, would influence both the Liberal and Conservative parties for the next half a century. Palmerstonianism entailed nothing less than a far-reaching vision for British global hegemony. The world would gradually move towards universal progress based upon British cultural norms and leadership. Trade, Christianity, education and constitutionalism would be advanced – with critics of the vision pointing to trade as Britain’s true motivation. Palmerstonianism also held no place for the “recalcitrant elites” of other societies, who were held to be “reliant upon privilege, corruption and superstition.” Shipping magnate Macgregor Laird dubbed Palmerston’s ideas as “the moral power of the 24 pounder.” None of this meant, of course, that Britain sought to conquer the entire world. Much of Britain’s hegemony rested on an “informal empire” of economic and political influence, with most of Latin America and the Confederate States falling into such a category.
This conflict between idealism and pragmatism would plague British politics and Britain’s role as a global power for the foreseeable future. While the independence of the Confederate States and the humbling of the Union cemented Britain’s pre-eminence, there was much soul-searching when it became clear that the result of the war had significantly strengthened the institution of slavery in the western hemisphere.
AN: Essentially, Britain's distraction in North America means Bismarck acts more decisively against Denmark. This in turn means German unification unfolds rather differently. Emperor Napoleon III manipulates the situation for the good of France, and Britain basks in its American triumph for the time being.
My impression with regards to France is that they would rather focus on Mexico than actively engage in the war beyond moral and financial support. I'm very much open to discussing this further, however.