▁had ▁been ▁lost ▁by ▁Soviet ▁Russia ▁in ▁the ▁Tre aty ▁of ▁Br est - L it ov sk ▁( 1 9 1 8 ) ▁were ▁an nex ed ▁by ▁the ▁Soviet ▁Union ▁after ▁World ▁War ▁II : ▁the ▁Balt ic ▁states ▁and ▁eastern ▁port ions ▁of ▁inter war ▁Poland . ▁The ▁Russian ▁S FS R ▁also ▁gained ▁the ▁northern ▁half ▁of ▁East ▁Pr uss ia ▁( K al ining rad ▁O blast ) ▁from ▁Germany . ▁The ▁Ukrain ian ▁SS R ▁gained ▁Trans car path ia ▁( as ▁Zak arp att ia ▁O blast ) ▁from ▁Czech oslov ak ia , ▁and ▁Ukrain ian ▁populated ▁Northern ▁B uk ov ina ▁( as ▁Ch ern iv t si ▁O blast ) ▁from ▁Roman ia . ▁Finally , ▁by ▁the ▁late ▁ 1 9 4 0 s , ▁pro - S ov iet ▁Commun ist ▁Part ies ▁won ▁the ▁elections ▁in ▁five ▁countries ▁of ▁Central ▁and ▁Eastern ▁Europe ▁( specific ally ▁Poland , ▁Czech oslov ak ia , ▁Hung ary , ▁Roman ia ▁and ▁Bulg aria ) ▁and ▁subsequently ▁became ▁People ' s ▁Dem oc ra cies . ▁These ▁elections ▁are ▁generally ▁regarded ▁as ▁rig ged , ▁and ▁the ▁Western ▁powers ▁recognized ▁them ▁as ▁show ▁elections . ▁For ▁the ▁duration ▁of ▁the ▁Cold ▁War , ▁the ▁countries ▁of ▁Eastern ▁Europe ▁became ▁Soviet ▁satellite ▁states ▁— ▁they ▁were ▁" in dependent " ▁nations , ▁which ▁were ▁one - party ▁Commun ist ▁States ▁whose ▁General ▁Secretary ▁had ▁to ▁be ▁approved ▁by ▁the ▁Kre ml in , ▁and