In May, 1937, Neville Chamberlain became prime minister of Great Britain. His program for dealing with Hitler was one of appeasement, that is, of attempting to meet German grievances in hopes of avoiding war. Hitler took advantage of this policy by annexing Austria on March 13, 1938. He then demanded the return to Germany of the Sudetenland, a part of Czechoslovakia inhabited largely by Germans. Czechoslovakia, assured by various treaties of the backing of France and the Soviet Union, prepared for war.
To avoid a major European war that would eventually involve Britain, Chamberlain flew to Hitler's mountain home at Berchtesgaden with the hope of resolving the crisis. Hitler merely increased his demands. On September 29, 1938, Mussolini, Chamberlain, and Premier Edouard Daladier of France met with Hitler in Munich. Without consulting the Czechs or the Soviets, who were allied with the Czechs, they agreed to the German annexation of the Sudetenland and other border areas of Czechoslovakia. Chamberlain, convinced that this would satisfy Hitler, proclaimed the agreement to be a guarantee of "peace in our time."
Great Britain and France increased production of armaments, particularly airplanes and antiaircraft guns. On March 31, 1939, Chamberlain announced complete support of Poland in its long-simmering dispute with Germany over the Polish Corridor and access to Danzig. (The Polish Corridor was a strip of Polish territory that separated East Prussia from the rest of Germany and gave Poland access to the Baltic sea.) France joined in supporting the Poles. In April, the first peacetime conscription in British history was announced. Guarantees of protection for other small states menaced by the Axis were also announced by Britain.
In August the world was surprised by the announcement of a nonaggression pact and trade agreement between Germany and the Soviet Union. This move, uniting two apparent enemies, gave Hitler the freedom to annex more territory in the east without fear of Soviet intervention. Secret clauses in the agreement divided eastern Europe into German and Soviet spheres of influence and provided for the division of Poland between the two countries.
Poland, aware of the significance of the German-Soviet pact, prepared to defend itself, and reminded Britain and France of their promises to help it resist aggression. With Hitler becoming increasingly belligerent and tensions mounting, Europe braced itself for war.