Why the world went to war in 1914

Why did so many men die in World War I for a cause that, to this day, seems unclear and confusing? As we mark the centenary of the start of the terrible conflict, we explain why the world went to war in 1914

Standing soldiers

Europe in the early 20th century was a powder keg. After decades of diplomatic difficulties, all it needed was a spark to set the whole continent ablaze.


That spark came with the assassination of the heir of the Austro-Hungarian Empire, Archduke Franz Ferdinand, on 28 June 1914. The Austrian was shot dead by a Serb, giving Austria justification to invade Serbia. Alliances were honoured, with Russia coming to Serbia’s aid and Germany to Austria’s. On 1 August, the two empires declared war on each other, prompting other European powers to mobilise their forces. World War I had begun.

The German command had long feared being trapped in a war on two fronts – with Russia on the east and France on the west – so an audacious pre-emptive attack had been planned years before. The Schlieffen Plan proposed a speedy and huge-scale invasion of France, crippling the French before they could mobilise. With one front already won, the army would then hurry its forces to the east. The plan was put into action on 2 August.

Germany invaded Luxembourg and declared war on France – but gained Britain as yet another enemy by attacking Belgium. Wanting revenge for the loss of the Alsace-Lorraine region in 1871, France proved a tougher adversary than the Schlieffen Plan anticipated. They successfully halted the German advance. Trenches were dug and the Western Front was formed.


For four years, a war of attrition dragged on, with Germany facing what they desperately wanted to avoid: a war on two fronts.