Answer: Great Britain and France declared war on Germany
Explanation: Germany invaded Poland on September 1, 1939, which officially began the Second World War. Britain and France declared a war on Germany on September 3, 1939, due to their guarantee of the unchanging of state border of Poland. Later it also resulted in the entry of other states into the war, there were various political agreements and deceptions. One of them was the attack of the Nazis on the Soviet Union despite the agreement that existed between them.
