In the early thirties, Churchill foresaw that Hitler's coming to power might have terrible consequences, and Germany's rearmament would pose a great threat to Britain and Europe. 1930 10 Churchill said in a conversation with the German prince Bismarck that he believed that Hitler or his followers would resort to force at the first opportunity. 1932 In May, Churchill warned the British House of Commons that war was coming. He believes that Germany is Britain's biggest enemy and France is Britain's ally, so he resolutely opposes the British government's policy of conniving at Germany's rearmament.

On September 1939, 1, Chamberlain called Churchill to Downing Street 10 and asked him to join the wartime cabinet as the Minister of the Navy.