Before World War II, Mussolini may have been preparing Ciano to succeed him as "Duce". At the start of the war in 1939, Ciano did not agree with Mussolini's plans and knew that Italy's armed forces were ill-prepared for a major war. When Mussolini formally declared war on France in 1940, he wrote in his diary, ""I am sad, very sad. The adventure begins. May God help Italy!"" Ciano became increasingly disenchanted with Nazi Germany and the course of World War II, although when the Italian regime embarked on an ill-advised "parallel war" alongside Germany, he went along, despite the terribly-executed Italian invasion of Greece and its subsequent setbacks. Prior to the German campaign in France in 1940, Ciano leaked a warning of imminent invasion to neutral Belgium.