Soviet Bloc

From Workers & Resources: Soviet Republic Official Wiki

The Soviet Bloc is one of the two trading partners in game, representing the Socialist or USSR-aligned nations. The bloc can be traded with at the customs houses at the edges of the map with red stars. The Bloc uses Rubles as currency, so anything bought or sold from the Bloc will be paid for with Rubles.

As the primary trading partner of the player's Republic, most vehicles are available only from the Bloc. Its counterpart is the Western Bloc.

In real life, the countries in the Soviet Bloc generally had tight bonds with the USSR, and some were even considered puppet states of the USSR. The Soviet/Eastern Bloc was "dissolved" in 1991 after the collapse of the Soviet Union, and most states formerly in the the Bloc were decommunized and went on to join NATO and the European Union.

Further Reading: Eastern Bloc on Wikipedia