World in Conflict: Soviet Assault is the first expansion to World in Conflict and shows the player the Soviet perspective of the war by putting him in the shoes of Lieutenant Romanov one night before the Iron Curtain falls. But instead of a separate campaign, the six Soviet missions with their ten new cutscenes are integrated into the original US campaign, starting with the Soviets. There are no new units on either side and the gameplay remains the same.

Besides the new campaign missions, the expansion includes three new multiplayer maps and upgrades the original game to Version 1.0.1.0 featuring, amongst other things, the removal of the SecuROM-protection, the addition of an option to choose the bot difficulty in skirmish and multiplayer matches and several bug fixes as well as balance changes.