In 1893 Elisabeth Förster-Nietzsche returned to her mother’s adopted home town of Naumburg in Germany. She had been living in Paraguay with her husband, Bernhard Förster, a nationalist and anti-Semite who had founded an Aryan colony to begin “the purification and rebirth of the human race”. Elisabeth’s brother, Friedrich Nietzsche, had condemned her husband’s anti-Semitism and her decision to join him in South America. The experiment failed in any case. Blighted by disease, poor harvests and intercommunal strife, the outpost collapsed in two years. Förster committed suicide in 1889. Around this time, Nietzsche began his final descent into madness and Elisabeth came back to take care of him and his legacy.

Nietzsche’s first book, The Birth of Tragedy, published in 1872 while he was a professor at the University of Basel, received marginal attention. It wasn’t until the 1890s that his writings gained a wide readership across Europe. Elisabeth soon took control of Nietzsche’s literary estate and, little by little, transformed him into an instrument of her fascist designs. She began to rework his notebooks and to clip, cross out and fabricate quotations, so that, in the public imagination, her brother went from an opponent of German nationalism to a lover of the fatherland, from the author of The Antichrist to a follower of the gospel, and from an anti-anti-Semite to a venomous ­Jew-hater. Before his death in 1900, Nietzsche had asked his sister to ensure that “no priest or anyone else utters falsehoods at my graveside, when I can no longer defend myself”. He could not have foreseen this betrayal by Elisabeth, as she cast him as the lodestar of National Socialism.

Since the 1950s, scholars have endeavoured to rescue Nietzsche from his asso­ciation with Nazism. Walter Kaufmann’s Nietzsche: Philosopher, Psychologist, Antichrist (1950) was a formative work in which the German philosopher became a humanist and progenitor of 20th-century existentialism. His thinking was directed not at the triumph of Teutonic supremacy but at reviving, as he wrote in Twilight of the Idols (1889), an “anti-political” high culture.

The problem was that, in stripping away the layers of external disfigurement that had built up and set over the years, Kaufmann and others denied Nietzsche an interest in politics. The task that Hugo Drochon sets himself is to reinsert some political content into Nietzsche and show that he had a systematic political theory. The result is a superb case of deep intellectual renewal and the most important book to have been written about him in the past few years.

Drochon’s study takes place against the backdrop of 19th-century Europe, as that is where Nietzsche’s account of politics – the fate of democracy, the role of the state and international relations – is best understood. Nietzsche’s sane life coincided with the main political events of his time. He served as a medical orderly in the Franco-Prussian War, witnessed German unification and experienced at first hand the traits of a modern democratic order: party competition, secret ballots, voting and the influence of mass media. He also lived through Britain’s and Russia’s “great game” for control over central Asia. He went mad in the year Bismarck tended his resignation to Wilhelm II.

Drochon traces Nietzsche’s “intelligible account of modern society” in response to these events. Inspired by the Greeks – especially Plato and his mission to legislate a new state and train the men to do it – Nietzsche wanted to establish a healthy culture in which philosophy and great art could be produced. He was certain that slavery was necessary for this (a view that led to his eventual split with Wagner). The “cruel-sounding truth”, he admitted, was that “slavery belongs to the essence of culture”, as the artistic class, “a small number of Olympian men”, is released from the drudgery of daily existence to focus on producing art.

His disagreement with Wagner over the role of slavery led Nietzsche to describe the genesis and decay of the state. He saw clearly, like Hobbes, that the state of nature was “the war of all against all”. But whereas Hobbes imagined the state arising through a contract, Nietzsche saw it originating from a “conqueror with the iron hand”, who “suddenly, violently and bloodily” takes control of a people and forces it into a hierarchical society. Nietzsche then plotted its evolution, from a space within which culture flourished to the modern Kulturstaat, in which culture was appropriated for its own sake. If the state’s birth was violent, its decay was slow and was linked to Nietz­sche’s notorious phrase about the death of God: given that the Christian God was no longer a self-evident foundation of morality upon which societies could support themselves, the state faced dissolution.

Tracing with great forensic skill the minutiae of Nietzsche’s arguments across multiple sources, Drochon never loses the overall narrative thread (an occupational hazard of studying the history of political thought). Nor does he shy away from his subject’s unsavoury views. If Nietzsche’s remarks on slavery were harsh enough, his thinking on eugenics, or his physiologically inflected theories about democracy (which he regarded as the victory of a slave morality – associated with the “dark-skinned and especially dark-haired man” – over a master morality of the “Aryan conquering race”) sound even more repellent. Without wishing to justify these ideas, Drochon reminds us that theories of racial classification were prevalent and acceptable modes of inquiry in the 19th century. It would have been strange if Nietzsche had not drawn on them.

His darker side notwithstanding, many of Nietzsche’s insights speak to our politics now. He foresaw the privatisation of the state, in which “private companies” (Privatgesellschaften) would assume the business of the state, including those activities that are the “most resistant remainder of what was formerly the work of the government” – that is, “protecting the private person from the private person”. He showed how democracies gave birth to aristocracies and could become hostage to a “herd morality”, majoritarianism and misarchism: “the democratic idiosyncrasy of being against everything that dominates and wants to dominate”. He explored the question of wage labour and the increasing hostility between workers and employers and predicted the erosion of trust in

public institutions.

Nietzsche also described how statesmen revive the kind of pathologies that are corrupting European and American societies at the moment: nationalism, racism, intellectual parochialism and political insularity. He knew what he was talking about: Bismarck’s power politics, a tribute to blood (war) and iron (technology), was a “petty politics” that divided nations and peoples. Nietzsche’s “great politics”, by contrast, imagined the unification of Europe led by a cultural elite, the class he termed “good Europeans”, bred by intermixing Prussian military officers and Jewish financiers. Continental union would not only constitute a geopolitical counterweight to Britain and Russia. Good Europeans would, as Drochon writes, create “a new trans-European culture, which itself is specially called on to lead a world culture”.

So, this book has come at the right time. In the light of Britain’s vote for Brexit, which threatens to take us back to a petty politics of nationalism and continental division, Nietzsche’s writings are more significant than ever. Those of us who desire a more integrated and peaceful union with our neighbours cling despairingly – and with receding hope – to his dream that, in spite of “the morbid estrangement which the nationality craze has induced and still induces among the peoples of Europe, owing also to the short-sighted and hasty-handed politicians . . . Europe wishes to be one”.

Nietzsche’s Great Politics by Hugo Drochon is published by Princeton University Press, 224pp, £34.95

Gavin Jacobson is a writer and book critic