The German occupation of Czechoslovakia was the final concession of the policy of appeasement. Hitler's pacts with Italy and the Soviet Union gave him the confidence to invade Poland. This act led Britain to declare war.
The British public celebrated their relief that war had been, for the present, avoided.
However, there was growing concern that Hitler was not, as Chamberlain believed, just another politician who was open to negotiation. Instead, increasing numbers of people believed that he would continue to behave aggressively and that war would come, sooner or later. Even Chamberlain began to build up British forces against that possibility.