The causes of the Second World War can be attributed to a combination of political failures and ideological shifts that shaped the global landscape in the decades leading up to the war. One of the significant contributing factors was the failure of the Treaty of Versailles, which ended the First World War but imposed harsh reparations on Germany, fostering resentment and economic instability. Additionally, the rise of Adolf Hitler and the Nazi Party in Germany played a crucial role; Hitler's aggressive nationalism and expansionist ideology incited militarism and conflict. Coupled with the expansionist ambitions of Italy under Mussolini and Japan, these elements created a volatile environment.
Furthermore, the League of Nations, established to maintain peace post-WWI, proved ineffective in curbing these aggressive actions, ultimately leading to international tensions. The immediate cause of the war was marked by the German invasion of Poland in 1939, which prompted Britain and France to declare war on Germany, initiating a global conflict that would engulf the world. This section underscores how a combination of political, economic, and ideological factors precipitated one of history's most devastating wars.