On September 1, 1939, German troops swarmed across the Polish border and unleashed the first Blitzkrieg the world had seen. Hitler had been planning his attack since March - ever since German troops occupied the remainder of Czechoslovakia. The Poles suspected as much and readied their defences. Unfortunately, the Poles based their defensive strategy on the experiences of World War I. Mobility was crucial - mobility provided by cavalry troops the Poles considered the best in the world. Indeed, their horsemen were probably the world's best - but horses offered little defence against tanks.
Britain and France had sworn to defend Poland. Honouring these obligations, the two countries sent ultimatums to Hitler demanding his withdrawal from Poland. Hitler declined to respond. On September 3, Prime Minister Chamberlain went to the airwaves to announce to the British people that a state of war existed between their country and Germany. World War II had begun.
The English translation of the following audio of Shōwa Emperor Hirohito's Imperial rescript of the termination of War World II may be difficult to read because of the format used.
In this speech, Churchill had to describe a great military disaster, and warn of a possible invasion attempt by Nazi Germany, without casting doubt on eventual victory. He also had to prepare his domestic audience for France's falling out of the war without in any way releasing the French Republic to do so, and wished to reiterate a policy and an aim unchanged - despite the intervening events - from his speech of 13 May, in which he had declared the goal of "victory, however long and hard the road may be".