Why The World Went To War in 1914

An artist captures the assassination of Archduke Franz Ferdinand and his wife Sophie, Duchess of Hohenberg

August 4, 1914 — In a radio broadcast to the people put out by the BBC on September 3, 1939, British Prime Minister Neville Chamberlain announced: “This morning the British Ambassador in Berlin handed the German Government a final note stating that unless we heard from them by 11 o'clock that they were prepared at once to withdraw their troops from Poland, a state of war would exist between us. I have to tell you now that no such undertaking has been received, and that consequently this country is at war with Germany.”

And so the Second World War truly began. It was only 25 years since Britain had declared war against Germany on August 4, 1914 and the First World War – which became known as “the war to end wars” – spread across the globe. But the circumstances surrounding the outbreak of hostilities in 1914 were nothing like as simple and direct as those in 1939.

In 1914 empires stretched across continents and each was eager to maintain its power and standing. The principal empires were those of Britain, France, Russia, Germany, Italy and Austria-Hungary, and countries within these empires formed alliances for mutual and self-protection.

On June 28, 1914, Archduke Franz Ferdinand, the heir to the throne of Austria-Hungary, was shot dead by a Serbian man who believed Bosnia should be controlled by Serbia and not Austria.

Because its leader had been assassinated, Austria-Hungary declared war on Serbia. Catastrophically, that opened Pandora’s Box and Russia took up the fight because it had an alliance with Serbia. But Germany had an alliance with Austria-Hungary, so Germany declared war on Russia.

Meanwhile, since control of Belgium would have allowed a foreign power to threaten invasion of the UK, or at least blockade its trade, preventing such a situation was a long-standing British strategic interest. So by the 1839 Treaty of London Britain guaranteed Belgian neutrality, by force if necessary.

Having dismissed the treaty as “a scrap of paper”, on August 3, 1914, Germany demanded unimpeded progress through any part of Belgium and when this was refused, invaded the next day. Belgium immediately asked for assistance under the 1839 Treaty and in response, Britain declared war on Germany.

Thus, the major players had taken to the field of battle: the Triple Entente, composed of France, Britain and Russia; opposed by the Triple Alliance of Germany, Austria-Hungary and Italy. But as the fighting intensified and spread across the world, alliances shifted and changed and more and more countries were sucked into the conflict.

Decisively, the United States, with its formidable manpower and vast wealth, declared war on Germany on April 6, 1917 and on Austria-Hungary in December, 1917. A ceasefire and armistice was declared in November the following year.

By that time the total number of military and civilian casualties in the war had been calculated at about 40 million. Estimates of the deaths range from around 15 to 22 million. About 23 million military personnel were wounded.

These terrible and shocking figures were eclipsed by the Second World War where estimates of the total number of people killed have ranged from 35 million to 60 million. The Soviet Union and China are believed to have suffered the most total casualties, while an estimated 5,800,000 Poles died, which represents about 20 per cent of Poland’s pre-war population. About 4,200,000 Germans died.

In all, the scale of human losses during the Second World War was vast, but nobody knows the true number. As the Oxford Companion to World War II declares: "Casualty statistics are notoriously unreliable”.

Published: June 5, 2023
Updated: August 6, 2023