1. World War I Chapter 15 Section 1

3. World War I The Big Idea World War I and the peace treaty that followed brought tremendous change to Europe. Main Ideas Rivalries in Europe led to the outbreak of World War I. After a long, devastating war, the Allies claimed victory. The war’s end brought great political and territorial changes to Europe.

4. Causes of World War I Nationalism, or devotion and loyalty to a country, increased in the 1800s. People across Europe wanted their countries to become large and powerful. Main Idea 1: Rivalries in Europe led to the outbreak of World War I As countries grew more powerful, rivalries began. Some countries were willing to go to war to prove their superiority over their rivals. Some countries strengthened their armies and created stockpiles of new weapons to prove their strength. Countries also began to form alliances, or agreements to protect each other, for added protection from their enemies.

5. The Spark for War A series of events in 1914 led to the outbreak of World War I: Tensions rose between Austria-Hungary and Serbia, both of which wanted the territory of Bosnia and Herzegovina. On June 28 a Serbian assassin shot and killed Archduke Francis Ferdinand, the heir to the throne of Austria-Hungary. Austria-Hungary declared war on Serbia. Serbia turned to its ally, Russia for help. Serbia’s other allies, Great Britain and France, also joined the war. They were called the Allied Powers. Germany joined the war on Austria-Hungary’s side. Together they were known as the Central Powers.

7. Main Idea 2: After a long, devastating war, the Allies claimed victory. Both sides dug deep ditches along the font lines. Trench warfare was dangerous, both from fighting and from hunger and disease as well. Millions of soldiers died, and neither side gained an advantage. New weapons, such as machine guns, poison gas, and tanks, were created to fight soldiers in trenches. The War Begins Germany sent troops into Belgium and France. The Allies stopped them outside Paris. Russia attacked the Central Powers from the east, forcing them to fight on two fronts. Trench Warfare The British navy blocked supplies from reaching Germany. German U-boats attacked British ships. The War at Sea

9. The Allies Win For three years the war was a stalemate. In 1917, however, it began to turn in favor of the Allies: German U-boats began to attack American ships. The United States warned Germany to stop, but these warnings were ignored. As a result the United States joined the Allied Forces. RussiansNewly arrived American troops gave the Allies an advantage, though the Russians soon dropped out of the war. Germany renewed its attack on the Allies, but that attack was stopped. The Central Powers surrendered in the fall of 1918.

10. Main Idea 3: The war’s end brought great political and territorial changes to Europe. Effects of World War I More than 8.5 million soldiers killed 20 million more soldiers wounded Leaders of the Allied countries met at Versailles in France to discuss the terms for peace after the war. Their decisions were recorded in the Treaty of Versailles. According to the treaty, Germany had to: –Accept blame for starting the war –Reduce the size of its army and give up its overseas colonies –Pay billions of dollars for damages caused during the war

11. Political Changes After World War I Russia World War I caused great hardship for people. During the war a revolution forced the czar, or emperor, out of power. Vladimir Lenin took over Russia’s government and established Communism in Russia. Communism is a political system in which the government owns all property and controls all aspects of life. Europe The German Empire was replaced by a German republic. Austria and Hungary became separate countries. Poland and Czechoslovakia gained independence. Yugoslavia was created. Finland, Estonia, Latvia, and Lithuania became independent.