Answer:
This is a reference to World War Two.
Explanation:
World War Two was the greatest conflict the world has ever seen. After signing the Molotov-Ribbentrop pact Hitler decided to attack Poland on September 1, 1939. Most of the European countries were involved in the conflict when in December of 1941 United States entered the conflict. Millions have died before the war ended in 1945 with the surrender of Germany and finally Japan.
