World War II was mainly caused by certain ideologies that made countries and dictators act violently to get what they want. Some of the main-long term causes include the rise of facism in Italy, the militarism of Japan, which invaded China in the 1930s and the Nazi takeover of Germany. Hitler's actions led other countries to realize he had to be stopped, while others were simply defending their territories against invasion. Hitler's Invasion of Poland was the trigger that caused Britain and France to get involved in the war and is seen by historians as the start of WWII
Some Main Long-Term Causes of World War II
Treaty of Versailles - the harsh stipulations of the Treaty of Versailles in an economically difficult time, left many Germans bitter and caused them to vote for the Nazi party.
Anti-Communism - When the communist Bolsheviks came to power in Russia with the aim to overthrow capitalism world-wide, supporting the setup of communist regimes in other countries, many Europeans were starting to fear a violent Communist revolution.
Expansionism - A couple of countries sought to expand their territories and benefit from that economically. Benito Mussolini wanted to establish a “New Roman Empire,” Hitler also wanted to claim back the “rightful” territories of Germany and expand further into Europe to create a Greater Germany and Japan wanted to conquer China to benefit from its economy and resources.
Failure of the League of Nations - The League of Nations was established after World War I with the aim to prevent a repeat war. Its policies however had no effect on the countries that were trying to expand, forcing the Allies to use violent means to stop them.
This article is part of our larger educational resource on World War Two. For a comprehensive list of World War 2 facts, including the primary actors in the war, causes, a comprehensive timeline, and bibliography, click here.