“People live by narrative,” Boris Johnson said in a recent profile for the Atlantic. “Human beings are creatures of the imagination.” It was a revealing line from a man who usually prefers to evade, but Britain’s journalist-statesman didn’t get to where he is today by underestimating the power of a good story. As for the question of what narrative Johnson himself lives by, some light can be shone by the book described as the “primer for Johnsonism”: Realpolitik: A History. It was written in 2015 by John Bew, who has since been plucked by Johnson from the war studies department of King’s College London to serve as his chief foreign policy adviser and help work out what “Global Britain” might actually mean. It is extremely rare for a British prime minister to invite a historian into his inner circle, but Bew – “one of the outstanding historians of his generation”, says Michael Gove – has already proved influential. He was a key author of “Global Britain in a Competitive Age”, published in March and the most comprehensive review of Britain’s place in the world since the end of the cold war. Among the review’s most eye-catching features is a promise to return to spending 0.7% of national income on development “when the fiscal situation allows” (which it hasn’t yet, it seems). Another is the clear-eyed identification of Russia as an “active threat” (China is merely a “systemic challenge”) and a commitment to expand Britain’s nuclear arsenal from 180 to 260 warheads. Britain’s highest international priority, however, is identified as climate change. Bew is an intriguing and contradictory figure. The fact that his most recent book is Citizen Clem, an Orwell prize-winning biography of the Labour prime minister Clement Attlee, shows that he is far from tribal. Citizen Clem is currently required reading for Labour MPs, meaning Bew, 41, commands a rare crossbench appeal. He grew up in Belfast where both his parents were history professors. He has worked for the right-leaning thinktank Policy Exchange and is a former Henry Kissinger chair at the US Library of Congress but has also written left-leaning essays for the New Statesman (including some notably harsh denouncements of David Cameron and Philip Hammond). He is said to be “Brexit-agnostic”. But none of this would be inconsistent with the principles of realpolitik, a term that has been much used in international relations since it was coined by the German liberal writer August Ludwig von Rochau in 1853, but which, Bew shows, has been distorted and misunderstood in the decades since. The world that Rochau faced in 1853 was one that a modern liberal might find oddly familiar. Disruptive technologies were interacting with new ideas about individual freedom in unpredictable ways; nationalism, sectarianism and inter-class rivalries were simmering; “great powers” were squaring up to one another. Then, as now, Europe was grappling with the “quintessential problems of modernity”, as Bew puts it. And liberals were bitterly disappointed at the way things had turned out. Ever since the defeat of Napoleon in 1815, German intellectuals such as Rochau had dreamed of uniting Germany’s small states into one modern, progressive nation. They were convinced history was on their side – that the bourgeoisie and new proletariat would inevitably win out over the corrupt old elites. “We don’t recognise this lazy nobility we now have, we reject our present class hierarchies,” says the idealistic medical student Morton in Thomas Mann’s novel Buddenbrooks. “We want all men to be free and equal, for no one to be someone else’s subject, but for all to be subject to the law.” In 1848, such ideals would animate uprisings not only in Germany but all over Europe, from Ireland to Romania, France to Bohemia, Denmark to Italy – a sort of 19th-century European version of the Arab spring. But as with the Arab spring, the autocrats emerged triumphant. The Prussian military leader Otto von Bismarck would ultimately show that nations were forged by “iron and blood” and not by elegant speeches. It was in this context that Rochau wrote Grundsätze der Realpolitik (Foundations of Realpolitik), drawing on his political disappointments as well as Karl Marx’s new theories of class consciousness and the conservative philosopher Edmund Burke. Rochau railed against the utopianism of his fellow radicals – their “formless words, impulses, emotional surges, melodic slogans, naively accepted catchwords [and] habitual self-delusions”. He didn’t abandon his ideals but realised that if liberals ever wanted their vision to prevail, they would have to get real. Hence: realpolitik. Bew’s Realpolitik was written six years ago, pre-Trump and pre-Brexit; when he mentions realpolitik in a 21st-century context, it is to contrast the nuanced foreign policy of Barack Obama with the war-waging ideologues who preceded him. However, it is in his summary of Rochau’s four key principles that you begin to see why the book might have “pinged” for Johnson. The first is that “the law of the strong is the determining power in politics” – so, it doesn’t matter if you “won the argument”, as Jeremy Corbyn protested after the 2019 election. It matters that you won the actual election. However, power often lies outside conventional politics, too; the art is to figure out where precisely it lies and how to use it. The second principle is that the most effective governments harness the competing social forces within a society. Harmonious nations are strong nations. If an opponent cannot be crushed, they must be assimilated. (So: if an opponent cannot be assimilated they may be crushed?) The third is that ideas do play a vital role in politics, but not because they are “right” or “true” or “moral”. They matter only insofar as people care about them. A nice idea like “eternal peace” has no political force. But the “craziest chimera” can become extremely important, argued Rochau – even if it is rooted in prejudice, ignorance or immorality. The German nationalist historian, Heinrich Gotthard von Treitschke, developed this idea further. An effective leader is able to awaken the “finer energies” in men, but shouldn’t ignore the fact that “stupidity and passion matter, and have always mattered in history”. All great leaders show a “touch of cynical contempt for mankind”. Johnson would echo this line in the Atlantic profile: “All romantics need the mortar of cynicism to hold themselves up.” And finally: the zeitgeist – “the consolidated opinion of the century” – is the most important factor in determining a nation’s trajectory. All leaders, even the strongest ones, are beholden to forces they cannot control. Coronavirus would be one such force. The rise of China, climate change, perhaps even the Black Lives Matter movement might be others. So being able to switch priorities, renege on commitments, make new friends and ditch old ones is not necessarily the weakness your opponents imagine it to be. One moment liberal, migrant-loving mayor of London; the next moment champion of the north and enemy of the “woke”. Sure enough, Johnson’s foreword to Global Britain in a Competitive Age emphasises the need for “agility and speed of action” as guarantors of British prosperity and security. “We must be willing to change our approach and adapt to the new world emerging around us.” But the afterlife of the term “realpolitik” shows how easily it can go awry. Rochau was soon forgotten, but his ideas were studied by Treitschke, who soon dispensed with the idealism: “We must become more radical in questions of unity and more conservative in questions of liberty,” he urged the new German nation in 1870. He was – in stark contrast to Rochau – a vicious antisemite. The term realpolitik would then become associated with Otto von Bismarck and the aggressive foreign policy of the early German empire. By the early 20th century, it was often used interchangeably with “machtpolitik” (the politics of might) and contrasted with British “idealpolitik” – since the British liked to claim their own imperial aggression was to serve higher ideals. The Germans would simply call this hypocrisy. But which approach was actually the more “realistic” in the long term? A country that remorselessly pursues “self-interest” with no appeal to public opinion or morality can hardly be said to have taken into account all the relevant factors. No one defends the German empire today – but the myths that sustained the British empire retain a freakish political power. In an American context, realpolitik would become closely associated with cold war strategists, notably Henry Kissinger (though he never used the term). It characterised the sort of “hard-headed” assessment of interests that might make carpet-bombing Cambodian farmers seem like a good idea, and was often contrasted to “Kumbaya”-singing peaceniks who just wanted everyone to get along. However, as Bew shows, Rochau always hoped to put realism at the service of idealism – and those who have claimed to have a firmer grasp of “reality” are often those who have come unstuck. One of the curious questions is: why would Johnson so readily identify with a set of ideas born of defeat? Rochau was addressing liberals who had been outmanoeuvred in the revolutions of 1848. Johnson picked the winning horse in the EU referendum and now leads a country that increasingly feels like a one-party state. It is true that one of the stranger features of British politics is that the more emphatically the Brexiters win, the more they behave like losers, full of grievances. An optimist might prefer to see Johnson as the idealist in this scenario – trying to work out how best to hold on to a freedom-loving liberalism. A pessimist might note that things didn’t really work out for the mid-19th century German liberals in the end. And the danger in the meantime is that Johnson becomes so reliant on the “mortar of cynicism” that he walls himself – and the country – in. As for the “crazy chimeras” – ideas that are politically powerful regardless of their merit – you don’t have to look too hard for those. GB News has a whole team on it. So apparently does the culture secretary. The fact that fishing accounts for 0.12% of British GDP didn’t stop it dominating the Brexit imagination. Likewise, 80 extra nuclear warheads won’t do a thing to make any of us safer – but that may not be the point. The former Labour MP Chris Mullin recently observed how popular nuclear weapons were in his old “red wall” seat of Sunderland South. “The merest suggestion that the UK could live without nuclear weapons induced apoplexy among some of my working-class constituents.” Another disquieting question is which of the competing forces in the nation can be harnessed, and which may be crushed? Is it really possible to “Rule Britannia” 16 million Remain voters into submission? But in the meantime, those dismayed by the way power operates in Johnson’s Britain would do well to brush up on their Realpolitik – as there are lessons here for them too.