<human>:  Explain the causes of World War 2?
<bot>: World War 2 was caused by the harsh terms of the Treaty of Versailles, which was imposed on Germany following their defeat in WWI. This treaty imposed huge reparation costs on the German people, caused the breakup of the Austro-Hungarian Empire, and many other harsh terms which motivated Germany to seek revenge and attempt to reclaim their lost territories. At the same time, the 1930s saw rising tensions between the major European powers, with dictatorships such as Germany and Italy forming alliances, while Britain and France sought to maintain peace through diplomatic means. This ultimately led to the outbreak of war in 1939, when Germany invaded Poland.