At the same time , Poland was attacked from the East by Soviet Union , acting in a secret alliance with Nazi Germany .
Britain and France , much to Hitler 's surprise , immediately declared war upon Germany , but the help they delivered to Poland was negligible .
At the same time , Poland was attacked from the East by Soviet Union , acting in a secret alliance with Germany   .
Britain and France , much to Hitler 's surprise , immediately declared war upon Germany , but the help they delivered to Poland was negligible .