World War I: Causes: The immediate cause of World War I was the assassination of Archduke Franz Ferdinand of Austria-Hungary by a Serbian nationalist on June 28, 1914. However, the underlying causes of the war were more complex, including imperialism, nationalism, and military alliances.
Events: The war began on July 28, 1914, when Austria-Hungary declared war on Serbia. Within weeks, Germany declared war on Russia and France, and Britain joined the war in response to Germany’s invasion of Belgium. The war quickly became a global conflict, with many countries, including the United States, becoming involved. The war ended on November 11, 1918, with the signing of the Armistice of Compiègne.
Consequences: World War I resulted in millions of deaths and widespread destruction. The war also led to the downfall of several empires, including the German, Austro-Hungarian, and Ottoman Empires, and the emergence of new nation-states. The Treaty of Versailles was signed in 1919, officially ending the war, but its harsh terms imposed on Germany were seen as a major contributor to the rise of Nazi Germany and the outbreak of World War II.
World War II: Causes: The immediate cause of World War II was the invasion of Poland by Nazi Germany on September 1, 1939. However, the underlying causes of the war were more complex, including the failure of the Treaty of Versailles, the rise of fascist regimes in Italy and Germany, and the aggressive foreign policies of these regimes.
Events: The war began on September 1, 1939, with the German invasion of Poland, and soon spread to include much of Europe, as well as Asia and Africa. The United States entered the war after the Japanese attack on Pearl Harbor on December 7, 1941. The war in Europe ended with the unconditional surrender of Germany on May 8, 1945. The war in Asia ended with the dropping of atomic bombs on Hiroshima and Nagasaki by the United States on August 6 and 9, 1945, respectively, and Japan’s surrender on September 2, 1945.
Consequences: World War II was one of the deadliest conflicts in human history, with millions of deaths and widespread destruction. The war also led to the downfall of the fascist regimes in Italy and Germany and the emergence of the United States and the Soviet Union as superpowers. The war had a profound impact on the world, leading to the creation of the United Nations, the establishment of the Cold War, and the beginning of the decolonization process in many parts of the world.
This is a brief overview of World War I and World War II, and you can learn more about them in detail as you prepare for the IAS exam.