I believe Hitler’s actions and the appeasement that followed it are the key reasons for the outbreak of World War 2.Hitler’s foreign policy was firstly German need more Lebensraum and secondly to unite all German speaking people under one Reich in a Pan-German Empire. He did this in 2 phases: Phase 1 - 1933-1937 – Cautious Expansion Phase 2 - 1937-1939 – Aggressive Expansion
Phase 1: In 1933 Hitler withdrew Germany from the League of Nations after storming out of the Disarmament Conference where no conclusion was reached because no country really wanted to disarm especially to the level of German which was only allowed 100,000 troops and 6 battleships and no air force. This meant that Hitler was free to do whatever he pleased and would not have to answer to the League of Nations.
Also in the same year Hitler, in July, Hitler announced the German rearmament and conscription which was against the Treaty of Versailles but no action was taken against him, not even a moral condemnation by the League of Nation which, though it was a pathetic attempt to stop the nation doing what it did by scolding it, should have been done to show Hitler that the League of Nations were against it. However you could argue that there no longer was a Treaty of Versailles because the allies had killed it long before, for example in 1924 they had re-negotiated reparations in 1924; allowed Hindenburg to deny War Guilt in 1927; in 1935 Britain even made a Naval-Arms agreement with Germany and therefore co-operated in overturning the Treaty of Versailles. In response to Hitler rearming Germany, Britain, France and Italy all signed the Stressa Front which meant that they would help each other if the Germans attacked – this is a sign of collective security.
Then in March 1936 Hitler even ordered his troops to march into the de-militarised Rhineland with orders to “back off at any sign of