The Ottoman Empire's Decline and Balkan Nationalism
The Ottoman Empire had been losing territory for decades, but by the early 1900s, the losses were accelerating. Former Ottoman provinces like Greece, Serbia, and Bulgaria had already broken away as independent states, and the remaining Balkan territories were restless with ethnic groups pushing for self-rule.
Several forces drove this instability:
- Balkan nationalism: Serbs, Bosnians, Albanians, and other ethnic groups increasingly demanded independence or unification with neighboring states that shared their identity.
- Pan-Slavism: This movement, backed by Russia, aimed to unite Slavic peoples across the region. Russia positioned itself as the protector of Slavic interests, which put it on a collision course with Austria-Hungary, the other major power in the Balkans.
- Great power competition: As Ottoman control weakened, Austria-Hungary and Russia both tried to expand their influence over the region. This turned local disputes into flashpoints for broader European conflict.
- Territorial disputes between new states: The newly independent Balkan nations fought among themselves over borders and populations, leading to the Balkan Wars of 1912–1913. These wars reshuffled territory and left multiple countries bitter and unsatisfied.
By 1914, the Balkans had earned the nickname "the powder keg of Europe." The combination of ethnic rivalries, great power meddling, and Ottoman collapse made the region dangerously unstable.
The Outbreak of World War I
From Assassination to European War
On June 28, 1914, a Serbian nationalist named Gavrilo Princip assassinated Archduke Franz Ferdinand, the heir to the Austro-Hungarian throne, in Sarajevo (the capital of Bosnia, then under Austro-Hungarian control). This single event set off a chain reaction that pulled all of Europe's major powers into war within six weeks.
Here's how the crisis escalated:
- Austria-Hungary blamed Serbia for the assassination and issued an ultimatum with deliberately harsh demands designed to be unacceptable.
- Serbia refused full compliance, though it accepted most of the terms. Russia backed Serbia as a fellow Slavic state.
- July 28: Austria-Hungary declared war on Serbia.
- Russia mobilized its army in support of Serbia, which Germany treated as a hostile act.
- Germany declared war on Russia (August 1) and then on France (August 3), Russia's ally.
- Britain entered the war on August 4 after Germany invaded neutral Belgium, violating a treaty Britain had pledged to uphold.
By early August 1914, most of Europe's major powers were at war. The alliance system that was supposed to deter conflict had instead guaranteed that a regional crisis would become a continental one.
Early Strategies and Battles
Both sides expected a short war. Their opening strategies reflected that assumption, and both failed.
Western Front: The Schlieffen Plan
Germany's plan was to knock France out of the war quickly by sweeping through neutral Belgium, bypassing the heavily fortified Franco-German border. The goal was to defeat France before Russia could fully mobilize its massive but slow-moving army. At the Battle of the Marne (September 1914), French and British forces halted the German advance just outside Paris. The Schlieffen Plan had failed, and both sides dug in. This was the beginning of trench warfare on the Western Front.
Eastern Front: Russia's Early Offensives
Russia mobilized faster than Germany expected and launched offensives into East Prussia to relieve pressure on France and Serbia. Germany responded with decisive victories at Tannenberg (late August 1914) and the Masurian Lakes (September 1914), inflicting massive casualties on Russian forces. However, Russia's invasion of Galicia (Austrian territory) was more successful, pushing Austria-Hungary back and exposing its military weaknesses.
The Shift to Total War
The failure of these opening plans had enormous consequences. With no quick victory possible on either front, the war settled into a prolonged, grinding conflict. The Western Front became defined by trench warfare and staggering casualties for minimal territorial gains. By 1915, the war had expanded beyond Europe, drawing in the Ottoman Empire, Italy, and other nations, and transforming a European conflict into a world war.