To a larger extent, the failure of the collective security paved the way for the Second World War (WWII). The aim of making attempts of collective security was to maintain world peace and avoid war, but due to lack of support from the countries, disagreement among powers and lack of enforcement power, the three attempts of collective security (i.e. The League of Nations, peace treaties and disarmament conferences) failed. The failure of the collective security increased the hostility among powers and encouraged Hitler and Mussolini to start foreign expansion, which posed a threat to the whole world and led to the outbreak of WWII.
However, there were other factors which brought about WWII .To a little extent, the Paris Peace Settlement paved the way for WWII. Since Italy failed to get what it thought it deserved in the Paris Peace Settlement, the Italians were very discontented. Therefore, Mussolini introduced totalitarianism, and started his foreign expansion by invading Abyssinia and Albania in 1935 and 1939 respectively.
Meanwhile, The Paris Peace Settlement also aroused the resentment and a strong desire for revenge among the Germans as they were suffered from the harsh treaty terms in the Paris Peace Settlement. Therefore, they supported the Nazi Party for revenge. As soon as the Nazi Party was in power, it rearmed Germany, sought to repudiate the Treaty of Versailles and planned for foreign expansion. For example, Germany invaded Poland and Czechoslovakia in 1939.
To a little extent, the Great Depression paved the way for WWII. The Great Depression had hit the USA, Britain and France badly. As they needed time to concentrate on rebuilding their own economies, they couldn’t stop the aggression of Hitler at the same time. The Great Depression had provided a favourable condition for Hitler to raise his Nazi party, which allowed him to form the Berlin-Rome-Tokyo Axis In 1937 and