On 1 September 1939, under the pretext of reclaiming the city of Danzig, German armed forces invade Poland. Honoring their diplomatic treaties and driven by the desire to maintain the balance of power in Europe, France and Great Britain swiftly declare war on Germany. This chain of events sets in motion the greatest war the world has ever seen: a Second World War. In the early years of the conflict, Germany display a successful incorporation of modern aircraft and tank technology into its traditional tactic of Bewegungskrieg. These tactics rely on deep penetrations by armoured forces, supported by aggressive air attacks and prove to be highly effective at encircling and finally destroying the enemy. Resulting in lightning fast victories, the new form of warfare is referred to as the Blitzkrieg. Set in this new theater of war, the new expansion for Order of Battle – WW2 puts the player in charge of the German Wehrmacht and Luftwaffe. Starting with the conquest of Poland, the campaign features the defeat of the Franco-British alliance on the western front, the invasion of the Soviet Union and finally the assault on Moscow in 1941.