After Order of battle: US Marines, Order of Battle is finally moving to the European theatre of war:

Order of Battle: Winter War is set during the war between Finland and Soviet Union, fought after only three months the Russian invaded Poland in agreement with the Molotov-Ribbentrop Pact.

This new expansion for Order of Battle includes the Winter War (1939-1940), the Continuation War (1941-1944) and the Lapland War (1944-1945). Players take control of the Finnish Army and, according to the shifting tides of war, against troops from Germany or the Soviet Union.

More information about this expansion is available here.