As WWI turned into a protracted, bloody struggle the initial enthusiasm gave way to growing class tensions which exploded first in Russia’s February Revolution.

In Vienna, St Petersburg, Berlin, Paris, and London, the outbreak of war had brought cheering crowds of patriots onto the streets. Strikes ended, protests were called off, and the barricades came down in working-class suburbs.

Leon Trotsky wrote of ‘the patriotic enthusiasm of the masses in Austria-Hungary’, Arthur Ransome in Russia of how ‘the moment welded the nation into one’, and Rosa Luxemburg of Germany’s ‘mad delirium’.

Not all were swept up. The crowds were predominantly middle class. The mood in the factories and the workers’ districts was usually more subdued.

But politics shifted sharply to the right, the leaders of the labour movement capitulated to chauvinism, and such anti-war voices as remained could get no hearing. Tens of millions backed the war enthusiastically, and tens of millions more felt they had no choice but to support their own troops.

Capitalism had not only plunged the world into an abyss of barbarism; it had also driven humanity mad with war fever.

But almost everyone expected a short war on the model of the Franco-Prussian War of 1870. The Germans hoped to be in Paris in six weeks. French soldiers wrote ‘à Berlin’ on the sides of their troop trains. British politicians announced that ‘the war will be over by Christmas’.

It was not to be. The war was protracted and of unprecedented ferocity – for the advanced industries of modern capitalism were capable of mass producing means of destruction on such a scale unknown in human history.

And as the investment in killing increased, war aims expanded to match the expenditure of effort. German leaders planned to dominate the whole of Central Europe, to annex the industrial regions of Belgium and eastern France, and to create a sphere of influence extending to the Balkans, Turkey, and the Middle East.

The British grabbed the German colonies in Africa and planned a carve-up of the Middle East between themselves, the French, and the Russians. The French wanted to re-conquer Alsace-Lorraine (lost in 1871) and had designs on the industrial Rhineland.

Military force had replaced economic competition as the primary mechanism for the expansion of capital. The outpouring of blood and treasure was to be made to return a profit.

The price paid by the soldiers, workers, and peasants of Europe was astronomical. Germany lost one in eight of its men of fighting age, France one in five. Millions more were maimed for life. Entire towns were decimated when local regiments serving at the front were sent ‘over the top’.

On the home front, there were wage cuts, rising prices, and food shortages as resources were diverted into war production. By 1917, German workers were getting on average only two-thirds of the required calories. Around 750,000 died of starvation before the war ended.

Society was turned upside down. Peasants who had never left their villages were sent to face death on distant battlefields. Young workers were taken from urban slums and hurled into the maelstrom of modern industrialised war. Women replaced men in the munitions factories and got their first taste of workplace exploitation.

Class tensions increased. Underfed soldiers living in waterlogged trenches under shell-fire grew resentful of staff officers camped out in country-houses behind the lines. Workers found that strikes were banned as living standards fell, while bankers and bosses grew rich on the profits of war.

By the winter of 1916/1917, the mood in the trenches and on the home front across Europe had grown sullen. A perfect storm was forming. But where would it break?

‘We of the older generation may not live to see the decisive battles of the coming revolution,’ remarked the exiled Russian revolutionary Lenin to a group of young workers in Zurich in January 1917.

Yet the very backwardness of Russia made the empire of the tsars one of Europe’s weakest links.

Russia’s participation in the bloody struggle for world domination was beyond her capacities. She was doomed by vast distances, primitive agriculture, a sparse rail network, and an industrial base too small to sustain armies of millions in a war of munitions.

‘In the first months,’ wrote Trotsky, ‘the soldiers fell under shell fire unthinkingly or thinking little; but from day to day, they gathered experience – bitter experience of the lower ranks who are ignorantly commanded. They measured the confusion of the generals by the number of purposeless manoeuvres on sole-less shoes, the number of dinners not eaten. From the bloody mash of people and things emerged a generalised word: ‘the mess’.’

Hunger and a sense of hopelessness gnawed at the peasant-infantry in their freezing trenches. Indiscipline and desertion became an epidemic. The line was held together by little more than flogging and shooting.

Hunger stalked the workers’ districts too. Still, on the morning of 23 February 1917, Tsar Nicholas II seemed as secure in his power as ever. No-one had the least inkling that a demonstration that day – International Women’s Day – would detonate the Russian Revolution.

The revolutionary underground had intended marking the day with nothing more than meetings, speeches, and leaflets. There had been no call to strike or to demonstrate.

It mattered not. Something had snapped. The masses would take no more. Women textile-workers came out on strike and then marched through the streets chanting ‘Down with high prices!’, ‘Down with hunger!’, ‘Bread for the workers!’.

As they passed other factories, they waved their arms, threw snowballs, and shouted for the workers inside to join them: ‘Come out!’, ‘Stop work!’. The movement swelled into a spontaneous ‘turn-out’ strike as the energy of street protest pulled one group of workers after another into action.

The following day, half of Petrograd’s 400,000 workers joined the movement, and now demands for cheap bread mingled with something far more ominous: ‘Down with autocracy!’, ‘Down with the war!’.

On that day and on those that followed, there were clashes with police, troops, and Cossacks. But not all were bloody. When Cossacks were ordered to charge 2,500 workers from the Erikson textile-mill, the horsemen passed down a narrow corridor made by their officers, and some smiled at the workers as they went.

‘Of discipline,’ comments Trotsky, ‘there remained but a thin transparent shell that threatened to break through any second.’

For five days (23-27 February 1917), the revolution hung in the balance as great masses of workers confronted the armed forces of the state in the streets of the capital. ‘There is no doubt,’ continues Trotsky, ‘that the fate of every revolution at a certain point is decided by a break in the disposition of the army.’

Whatever his own grievances and discontent, however great his silent sympathy with the people he is ordered to shoot down, the soldier takes a terrible risk when he turns on his own officers. To find the confidence to mutiny, he must feel that the mass before him has the strength and determination to win.

This matter was decided in a thousand encounters, big and small, on the streets of Petrograd during those five days. It was decided by a look, a smile, a resonant slogan; by the appeal of a starving mother against the order of a brutal officer; by the press of common humanity in a crowded thoroughfare; by the micro-biology of revolution.

On the fourth day, a wave of mutinies swept through the barracks. Workers and soldiers merged on the streets and paraded together with guns and red flags. New regiments arriving from the front to restore order were carried along on the revolutionary tide.

The generals had lost control of their army. They informed the tsar there was no possibility of regaining it without his abdication. The empire of the tsars had been destroyed in five days of proletarian revolution. Russia was a republic.

But what sort of republic? How would it be governed? Who would now rule? And would the people get the bread and peace they demanded? These questions remained to be answered. The Russian Revolution had only just begun.