Rival alliances, clashing interests, and secret treaties divided pre-war Europe, and set the stage for a war that would quickly engulf most of the continent, and much of the world.
The Triple Entente vs. the Central Powers
At the start of the war, the Triple Entente powers were:
- Great Britain
On the other side, were the Central Powers:
The Ottoman Empire, often known as Turkey, was not part of the Central Powers alliance in August 1914, but it had declared war on most of the Entente Powers by the end of 1914. In October 1915, Bulgaria joined the Central Powers.
Italy, a pre-war ally of Germany and Austria-Hungary, entered the war in 1915 on the side of the Entente. By 1918, many other countries had become involved, including the United States and Japan on the Entente’s side.
Causes of Tension
Long-standing territorial grievances, colonial competition, and fear of surprise attack plagued international relations in the run-up to war. Once fighting seemed likely, no state wanted to mobilize last, lest its enemies use the opportunity to settle old scores. Mobilization schedules, martial rhetoric, and secret obligations set most of Europe on the path to war.
All of the Great Powers of Europe had national interests that they hoped would be achieved by going to war.
- France was desperate to avenge its defeat by Germany in the Franco-Prussian War of 1870-1871 by regaining the lost provinces of Alsace and Lorraine.
- Russia promised to support Serbia, a fellow Slavic nation, while also ensuring that Austria-Hungary did not expand its influence in the Balkans.
- Great Britain supported Belgium and guaranteed its sovereignty, but also desired to retain the balance of power in Europe by restraining Germany.
- Italy, initially allied to the Central Powers, refused to be drawn into what it viewed as their war of aggression, but in May 1915 joined the Entente hoping to acquire territory from Austria-Hungary and new colonial possessions, mainly in Africa.
- Austria-Hungary wanted to suppress Serbian nationalism and to strengthen the unity of its empire, especially in the Balkans.
- Germany supported Austria-Hungary in its war on Serbia. It also sought greater influence in Europe, primarily by reducing the strength of France and Russia, and more colonial possessions.
- The Ottoman Empire (Turkey) wanted greater territorial control over the Turkic peoples, many of whom lived in Russia, and to secure its frontiers, mainly against Russia.