What triggered the start of the Second World War?

The Second World War was triggered by Germany's invasion of Poland on 1st September 1939.

The roots of the Second World War can be traced back to the Treaty of Versailles, which ended the First World War. The treaty imposed harsh penalties on Germany, including significant territorial losses, disarmament, and reparations. These conditions led to economic and political instability in Germany, creating a fertile ground for the rise of Adolf Hitler and the Nazi Party. Hitler's aggressive foreign policies and expansionist ideology are widely regarded as the primary causes of the start of the Second World War.

In 1939, Hitler signed a non-aggression pact with the Soviet Union, known as the Molotov-Ribbentrop Pact. This agreement allowed Hitler to avoid a two-front war, freeing him to invade Poland. On 1st September 1939, Germany launched a blitzkrieg, or 'lightning war', against Poland. This invasion marked the start of the Second World War. Britain and France, who had guaranteed Poland's borders, declared war on Germany on 3rd September 1939.

Hitler's invasion of Poland was a clear violation of the Treaty of Versailles, which had sought to maintain peace in Europe after the devastation of the First World War. The invasion demonstrated Hitler's disregard for international agreements and his intent to expand German territory, in line with his concept of 'Lebensraum', or 'living space'.

The start of the Second World War was not just a result of Hitler's aggression, but also of the failure of the League of Nations and the policy of appeasement pursued by Britain and France. The League of Nations, established after the First World War to maintain peace, proved ineffective in preventing aggression by its member states. The policy of appeasement, which involved making political or material concessions to an aggressive power to avoid conflict, also failed to prevent the war. The Munich Agreement of 1938, in which Britain and France allowed Germany to annex the Sudetenland region of Czechoslovakia, is a notable example of this policy. This agreement was seen by Hitler as a sign of weakness, encouraging him to continue his aggressive policies, ultimately leading to the invasion of Poland and the start of the Second World War.