Answer:
The answer to the question: How do you know that Berliners expected a retaliatory air strike following the attack on Poland, would be, that through this attack, all the wishes for apeacement ceased to exist, and the West, especially Britain and France, became aware that Hitler, and Nazi Germany, intended to continue invading European nations. In short, the true plans of Hitler finally came into clear view. The British and French also realized that Germany had become a real threat.
Explanation:
The invasion of Poland, which happened in 1939, nailed the coffin for the temporary peace that had been reached in 1938, through the Munich Conference. After the disappearance of Czechoslovakia, and after a Nazi-Soviet Pact, emboldened by the way he had achieved success and kept Britain and France at bay, Hitler pushed his military to initiate the invasion of Poland, even after knowning that there had been a pact between Britain and Poland in case of a German threat. After the invasion started, Britain and France declared war on Germany, on 3rd September 1939, and the Germans also knew that the war had started for real for them. It was only a matter of time before the German people would expect to feel the consequences of what Hitler had initiated.
