At the 1907 conference of the Second International (the organisation of European socialist parties) Rosa Luxemburg helped write a resolution committing each party to opposing its own government in a time of war.
She argued that workers of all countries had more in common with each other, than they did with their own bosses.
Many in the leadership of her party, the German SPD, were happy to support the resolution, believing it unlikely that there would be a war to test their resolve.
Others thought that the way to prevent war was to persuade the ruling class that imperialism wasn’t in their best interests – which in practice meant not challenging the government’s foreign policy.
Luxemburg insisted that the only way to put an end to war was to create a different society.
She explained that competition between countries for land and power isn’t just the result of the stupidity or greed of politicians, but the only way capitalism can continue growing.
This argument that capitalism can only grow at the expense of millions of lives was to divide the SPD.
The SPD had been moving away from revolutionary ideas for more than a decade, ever since the debates over reform versus revolution.
Luxemburg became the leading theoretician of the party’s radical wing. Unlike the Russian socialist Vladimir Lenin, who was also often in a minority, she didn’t attempt to organise a group around her politics.
The result of that failure was that power remained with the right wing of the party.
When the First World War broke out in 1914 SPD deputies in the German parliament voted to back the government.
They argued that since the war had started, Germany must fight to protect her “civilisation”.
Socialist parties across Europe followed their example and the International quickly fell apart.
Luxemburg and others campaigned hard against the war but their previous failure to build a group around them meant they were starting from scratch – and with such limited numbers they were forced to remain inside the pro-war SPD.
In 1915 Luxemburg was sent to prison for inciting soldiers to disobedience. She carried on writing anti-war articles but there wasn’t an organisation to publish them.
She helped form the Spartacus group inside the SPD in 1916, and it met with some initial success – 10,000 people joined the group’s first anti-war demonstration.
But the Spartacists had little alternative than to rely a few leaders who were easily targeted by police, and Luxemburg was quickly rearrested.
Germany erupted in a wave of sympathy strikes with the Russian Revolution in 1917. And even after they died down, widespread anger about the war and food shortages remained.
October 1918 saw a mutiny at a naval base and rebellion spreading to other towns. It quickly turned into a full scale revolution.
Luxemburg was released after the prison holding her was broken open by the revolt. The German ruling class were terrified. They negotiated with the SPD, offering power in return for ending the uprising.
The party’s leader, Friedrich Ebert, was made head of government, and his first act was to plan a military attack on workers in Berlin who had led the revolution.
In December 1918 Luxemburg finally broke from the SPD to form the Communist Party (KPD). After spending decades in a million-strong party, she now had just a few thousand supporters.
They were enthusiastic but mostly inexperienced – forming a party in the middle of a revolution hardly leaves time for training.
In January the government moved to smash the revolution, provoking an uprising in Berlin as an excuse to send in the army.
The revolutionaries fought back, but the other side was stronger.
The government blamed the KPD for the violence and started mass arrests. Luxemburg refused to go into hiding and on 15 January 1919 she was caught and murdered.
Luxemburg’s isolation and murder were a disaster for the socialist movement.
But her ideas, her belief in ordinary people’s ability to change the world, and her refusal to accommodate to the system went on to inspire future generations to fight for socialism.