Hearts of Iron IV No Step Back is the fourth major expansion for Hearts of Iron IV focused on revamping the politics and military of one of the last major powers of WW2 that have yet received a major rework since its launch, the USSR. Improving the authenticity of one of the hardest fought fronts in World War II, the eastern front, more specifically it adds greater detail to the many eastern European nations that were part or in close relations to the Soviet Union, making it so that it more closely reflects the soviet politics and policy at the era.
You will need the base game of Hearts of Iron 4 to access this DLC content.