The independent course taken by Tito's Yugoslavia in 1948 caused Bulgaria to seal the Yugoslav border; a 1953 Balkan Pact among Greece, Yugoslavia, and Turkey further isolated Bulgaria, which by that time had cut all relations with Western countries. The Soviet Union now was Bulgaria's only ally. It supplied military and economic advisers and provided the model for Bulgarian social services, economic planning, and education in the early 1950s. Over 90 percent of Bulgarian exports and imports involved Soviet partnership, although the Soviets often paid less than world prices for Bulgarian goods. Because the primitive, mainly agricultural Bulgarian economy closely resembled that of the Soviet Union, Soviet-style centralized planning in five-year blocks had more immediate benefits there than in the other European states where it was first applied in the early 1950s.

Data as of June 1992