After the Great War of 1914-18, European powers were desperate to avoid another conflict of that scale. But just 20 years later, they found themselves plunged into catastrophe on an even greater scale. The outbreak of World War Two has been blamed on the policy of 'appeasement' - with the Great Powers of Europe failing to stand up to German leader Adolf Hitler's aggressive foreign policy until it was too late. Tim Bouverie, author of Appeasing Hitler: Chamberlain, Churchill and the Road to War, comments on the gathering storm of the 1930s, unleashed in September 1939.