World War I: Causes, Key Events, and Aftermath

Undersea Warfare

The war at sea reached a stalemate. After a battle, in which neither Great Britain nor Germany achieved a decisive victory, German U-boats targeted enemy ships, including American vessels. This action ultimately led to the United States' entry into the war, with disastrous consequences for Germany.

The Paris Peace Treaties

Five separate peace treaties, collectively known as the Paris Peace Treaties (1919-1920), formally ended World War I. Each treaty was signed with a defeated power in a palace near Paris. Treaties were signed with Germany (Treaty of Versailles), Austria, and Bulgaria in 1919, and with Hungary and Turkey in 1920.

The League of Nations

In January 1920, the League of Nations was established in Geneva, Switzerland. This international body aimed to maintain world peace and uphold the post-war order. Intended to include all independent states, its mission was to resolve international disputes peacefully. However, the League faced numerous challenges from its inception.

The Outbreak of World War I (1914-1918)

The war initially erupted in Europe, with the primary belligerents being European powers. Due to their extensive colonial empires, clashes also occurred on other continents. Japan and the United States intervened in the conflict, along with Brazil (in solidarity with the U.S.) and China (due to its allies in the Far East). The involvement of these nations transformed the conflict into a global war.

The war began in the Balkans, a region marked by conflict since the 19th century. On June 28, 1914, Archduke Franz Ferdinand of Austria and his wife were assassinated in Sarajevo. Austria-Hungary used this event as a pretext to impose demands on Serbia, which involved Austrian intervention in Serbian affairs. Serbia's refusal led Austria-Hungary to declare war on July 28.

In 1908, Austria-Hungary's annexation of Bosnia threatened Serbia, prompting Russia to mobilize its troops. Germany, Austria-Hungary's ally, demanded that Russia halt its mobilization and that France remain neutral. On August 1, Germany declared war on Russia, and on August 3, on France.

The Central Powers consisted of Germany, Austria-Hungary, the Ottoman Empire, and Bulgaria. The Allied forces included Romania, Greece, Japan, and Italy. Italy, initially allied with the Central Powers, joined the Allied bloc led by France and Britain. The United States joined the Allies in 1917.

Underlying Causes of the War

The Allies blamed the defeated Central Powers, particularly Germany, for the conflict. However, the true causes were more complex:

• Western diplomacy relied on the use of force.
• Authoritarian and undemocratic governments were not accountable to their parliaments. To gain public support, they manipulated public opinion using nationalism, imperialism, and xenophobia.
• Economic interests, both in Europe and overseas, were considered national interests to be defended with military force.
• The arms race led to a constant build-up of military power in an attempt to deter potential adversaries.