Interaction of Customs Union and Common Economic Space States in Economic and Financial Spheres Is a Key Factor of Their Sustainable Development

The ambitious project of Eurasian integration, began in 2010 with establishment of the Customs Union, is entering in a decisive phase. Possible depth and desired coverage of unifying movement are identified, time has corrected the principles of interaction with each other and with potential participants. This article describes the Customs Union operation and the integration prospects within the Common Economic Space.