Which country was NOT part of the Soviet Union?

Romania was not part of the Soviet Union. Romania was part of the Eastern Bloc during the Cold War, which was a group of socialist states in Central and Eastern Europe that were under the influence of the Soviet Union. However, Romania pursued a more independent foreign policy compared to other Eastern Bloc countries. In the 1960s and 1970s, Romania, under the leadership of Nicolae Ceaușescu, distanced itself from the Soviet Union and pursued a more nationalistic and independent path. Ceaușescu criticized the Soviet invasion of Czechoslovakia in 1968 and refused to participate in the invasion alongside other Warsaw Pact countries. Romania maintained a certain degree of autonomy in its domestic and foreign policies, which set it apart from the more closely aligned Soviet satellite states. This independent stance eventually led to strained relations with the Soviet Union, and Romania was not fully integrated into the Soviet sphere of influence. As a result, Romania was not part of the Soviet Union, even though it was part of the broader Eastern Bloc.