Ethnic and border disputes disrupted trade such as the case of Bulgaria by the Kosovo war. There are several approaches that can be used to convert a centrally planned economy into a market economy. One is called The Big Bang Approach where sweeping reforms are implemented immediately. Prices are free from state control to seek market determination and the currency unit is devalued to reach a level of consistency with the international currencies. State subsidies are eliminated, interest rates are allow to rise, and state enterprises are turned loose to compete on their own.
Wages are free from state control and determined by the market.
This approach creates unemployment and rise in the prices of goods and services. The second approach is the Gradual Approach in which the changes will be spaced out over time to prevent economic disruptions such as inflation and unemployment. The problem with this approach is that, for example, the market economy can not work with centrally planned economy. The rest of the world remains with those countries which are neither developed or former communist bloc countries and emerging economies. They are often called third world countries.