Before we leave the centenary year of the outbreak of war in 1914 there’s someone we should talk about. Everyone now knows about the famous Christmas truce and football matches. But this was a war that was meant to have been “over by Christmas” 1914, not dragging on for four blood-soaked years. Plenty share blame for that, but one major culprit who seems to have been conspicuous by his absence in 2014 deserves a name check: Otto von Bismarck.

I’m astonished by this. Cynical and brilliant, an empire-builder who proclaimed the supremacy of “iron and blood” – actually it was his friend, Alfred (“Cannon King”) Krupp’s new guns made of steel that shed the blood – the Prussian chief minister turned first pan-German chancellor became the dominant European statesman of the 19th century, a near contemporary of Abraham Lincoln, a better man with a better legacy (and much better jokes).

Unlike the gentle 16th US president (1861-65) the highly aggressive Bismarck was far from a reluctant war-maker. In power from 1862 to 1890 he engineered three short wars – they’re where the word “blitzkrieg” comes from – against Denmark (1863), Austria (1866) and France (1870) to turn Prussia into the Second Reich (1871-1918) – the first had been medieval – and fatally undermined Germany’s fragile liberal institutions at a critical stage of their evolution.

What Germans got instead was a militarised monarchical autocracy sustained by rampant nationalism and supported by intellectuals of all kinds – sociologist Max Weber later repented his enthusiasm – who should have known better. Parliament was marginalised, the parties manipulated against each other, and Bismarck threatened to resign whenever he was seriously challenged. It was outrageous and it ended in the ruins of Berlin of 1945.

Yes, Bismarck spent the last 20 years of his career protecting the peace in Europe before the idiot new Kaiser, Wilhelm II, sacked him (Punch’s cartoonist famously portrayed it as “Dropping the Pilot”). But the damage was done. Bismarck had built a racing car only he could drive.

This kind of behaviour always matters because there are usually talented politicians around who see military adventurism and democratic corner-cutting as a tempting path to domestic ascendancy and wider prestige. Vladimir Putin seems to be ticking some boxes – witness this week’s intimidatory conviction of a promising opponent – but there are others in sight. Close to home Turkey’s Recep Erdoğan strikes me as a clever man with a dangerous lack of scruple. And, before anyone mentions Margaret Thatcher, she was usually rather cautious and sensitive to parliament, more so than Tony Blair was, I am sorry to say.

After its humiliations at the hands of Napoleon, 19th century Prussia’s was – even more than under Frederick the Great – a conscious process of self-aggrandisement. Plenty resisted the trend and Bismarck’s “iron and blood” exposition of his realpolitik ambitions in 1862 nearly got him fired before he started. He was not charismatic, soft-spoken, even hesitant, but utterly dominant over his king and even the powerful military, which privately mocked his weakness for uniforms. Try this interview with his biographer Jonathan Steinberg for a flavour of him. “This man means what he says,” Benjamin Disraeli concluded. Scary.

Roman history was again in vogue in Germany when in 1871, Bismarck’s patsy, Wilhelm I, king of victorious Prussia against Napoleon III, copied the Russian tsars and got an upgrade to Caesar – the new German Kaiser – proclaimed in the Hall of Mirrors at occupied Versailles. Less than 50 years later the defeated Germans were back in Versailles to accept an unjust, dictated peace in 1918, itself overthrown with a vengeance by Hitler in 1940.

Thank goodness the good Germans, the Germans of Beethoven and Schiller, have been back in charge since 1945, the kind of high-minded moderate people who were sidelined in the Bismarck era after the failed bourgeois revolution of 1848. They make their share of mistakes – the eurozone’s economic policies are largely shaped in Berlin – but they are not to be equated with the dreadful legacy of Kaiser Bill, let alone of Adolf Hitler, despite what unimaginative Eurosceptics say after reading the Daily Express.

Why does Bismarck escape blame as the chief architect of 20th-century Germany – and thus the man who created a militarised political machine that only he could handle? He used to get plenty of blame, but historical memory does funny things and the enormity of Hitler’s regime (he was “Vienna’s revenge on Berlin” wrote AJP Taylor) seems to have blotted out the significant past. When I ask Germans now they sometimes say: “Well, Bismarck is remembered mostly for the social security system he set up,” one designed to neutralise the appeal of socialism, still recognisable and admired today.

We can follow that line of argument. Bismarck’s Reich pioneered the modern welfare state, copied by others, including progressive British Liberals such as David Lloyd George and Winston Churchill between 1906 and the outbreak of war. Much criticism can be made of both of them over long careers, but neither was a militarist or would-be autocrat, bent on destroying accountable government.

Churchill was quite soppy about parliament. At a perilous moment in 1917 he told a fellow Liberal MP in the darkened Commons that “this little room is the shrine of the world’s liberties”, one that would decide the outcome of the war. “It is for the virtue of this that we shall muddle through to success and for lack of this Germany’s brilliant efficiency leads her to final destruction.” If we throw in a little help from the US and the British empire he was right about that – twice. You can imagine Abraham Lincoln saying it – but never Bismarck.

In any case there is a sense in which the first world war was indeed over by Christmas 1914, only Bismarck’s autocratic heirs couldn’t accept it. Unlike in 1870 and again in 1940 the Germans had failed to take Paris in another lightning war that summer. At great cost in lives the armies of the despised French Third Republic – shovelling troops up from the capital in buses and taxis – and Britain’s “contemptible little army” (Kaiser Bill’s phrase) held the line at the first battle of the Marne, just 30 miles north-east of Paris.

It had been a close thing, but on 11 September Helmuth von Moltke, German commander and nephew of the victor of 1870, ordered a retreat to the river Aisne, lines that would be “fortified and defended”, he ordered – in other words trenches. They soon stretched 600 miles from the Channel to the Swiss frontier. Blitzkrieg turned into “iron and blood” stalemate, much as it had in the trench warfare of Abraham Lincoln’s US civil war (1861-65) if anyone had noticed.

Moltke was replaced as chief of the German general staff three days later, but the war went on: four Christmases, including one truce, to go. The winners would be the ones with the deepest pockets, not with the biggest Krupp gun or the silliest helmets.