04 The First World War and the Remaking of Empires

From Balkan crisis to world war

Before 1914, rivalries among great powers, arms competition, imperial ambitions, and nationalist movements shaped European politics. Alliances offered security but also risked widening a conflict. In the Balkans, the weakening Ottoman Empire and competing national claims brought Austria-Hungary and Russia into rivalry.

The immediate crisis began on June 28, 1914, when Bosnian Serb nationalist Gavrilo Princip assassinated Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, in Sarajevo. Austria-Hungary blamed Serbia and declared war on it on July 28.

During the July Crisis, Germany supported Austria-Hungary, Russia mobilized, and Germany invaded Belgium on its way to attack France. Britain entered the war after Germany violated Belgian neutrality. The assassination was the trigger, but the conflict’s scale resulted from political choices, military plans, and existing rivalries—not from an automatic alliance mechanism.

A global and industrialized war

The Central Powers—Germany, Austria-Hungary, the Ottoman Empire, and Bulgaria—fought the Allied Powers, including France, the British Empire, and Russia, and later Italy and the United States. Fighting reached Europe, Africa, the Middle East, and the seas. Soldiers and laborers from colonies and other imperial territories served in campaigns far from home, making the war global as well as European.

On the Western Front, German forces were stopped in 1914, and armies dug extensive trench systems across France and Belgium. Repeated offensives at Verdun and the Somme caused enormous casualties without decisive results. On the Eastern Front, the armies covered a much longer front, and the balance shifted repeatedly. Major campaigns also took place in the Balkans, at Gallipoli, in the Middle East, and in Africa. Naval warfare and aircraft added further dimensions to combat.

Governments mobilized factories, transport, food supplies, and civilian populations to sustain the fighting. Machine guns, heavy artillery, aircraft, submarines, and poison gas made warfare more destructive.

The war’s final years

In 1917, revolution brought down Russia’s monarchy. After the Bolsheviks took power, Russia withdrew from the war and signed the Treaty of Brest-Litovsk with the Central Powers in 1918. The United States entered the war on the Allied side in April 1917.

In 1918, Allied offensives and the exhaustion and collapse of Germany’s allies brought the fighting to an end. Germany signed an armistice on November 11, 1918. The armistice stopped the fighting, but it was not the final peace treaty.

Four empires fall

War, revolution, military defeat, and nationalist movements dismantled four prewar empires:

• Russian Empire: The revolutions of 1917 ended Romanov rule. The Bolsheviks established a new government, while civil war and conflicts over territory shaped the former empire’s future.

• German Empire: The emperor abdicated in November 1918, and Germany became a republic. The state survived, but the peace settlement took its territory and all its overseas colonies.

• Austro-Hungarian Empire: The Habsburg monarchy broke apart in 1918. Austria and Hungary became separate states, and new or enlarged states—including Czechoslovakia and the Kingdom of Serbs, Croats, and Slovenes—emerged from former Habsburg lands.

• Ottoman Empire: Defeat and internal upheaval ended Ottoman rule over much of the empire. Turkish nationalist forces rejected the Treaty of Sèvres; the Treaty of Lausanne in 1923 established the internationally recognized borders of the new Republic of Turkey.

New borders reflected national claims only in part. Many people became minorities in successor states, and disputes over territory, citizenship, and political power continued. The Russian Revolution also created a communist state that challenged the existing political and social order.

The Paris peace settlement

The Paris Peace Conference opened in January 1919. The leading decision-makers were the leaders of France, Britain, the United States, and Italy. Defeated powers and revolutionary Russia were largely excluded from the negotiations, which produced separate treaties with the defeated states.

The Treaty of Versailles, signed with Germany on June 28, 1919, required Germany to surrender territory and its colonies, restrict its armed forces, and accept responsibility for losses for which the Allies sought reparations. Many Germans viewed the terms as imposed and humiliating.

The treaties redrew Europe’s borders and created or recognized new states, but they did not apply self-determination consistently. Strategic interests and competing national claims shaped decisions, and many populations were left outside the state they considered their national home. The settlement ended the fighting without resolving all the conflicts that had helped produce it.

Imperial control and collective security

Germany’s former colonies and much of the Ottoman Empire’s Arab territories were not granted immediate independence. Instead, the League of Nations assigned them as mandates, administered mainly by Britain and France under an international framework. This changed the legal language of empire but often preserved imperial control in practice. The arrangement, along with wartime promises and expectations of self-rule, fueled grievances among colonized peoples.

The settlement established the League of Nations to provide a forum for resolving disputes and to support collective security. The United States did not join: the U.S. Senate rejected the Treaty of Versailles despite President Woodrow Wilson’s central role in promoting the League. Without universal participation and effective means to enforce its decisions, the League struggled to prevent later aggression.