Belarusian Prime Minister Sergei Sidorsky will not participate in a May 28 customs union meeting between Russia, Belarus and Kazakhstan in St. Petersburg, Sidorsky's press secretary announced the same day, without giving any reasons for Sidorsky's absence. This development comes as no surprise to STRATFOR, as it is only the latest move in a series of arguments and holdouts between Russia and Belarus over Minsk's dissatisfaction with how Moscow has treated it economically. The customs union that Russia, Belarus and Kazakhstan launched Jan. 1 has had a rocky start involving several disputes among its members, and Belarus has been particularly argumentative. The union, a Moscow-led project that aims, gradually and through multiple stages, to increase economic integration among the three former Soviet countries, is only the beginning of the "common economic space" Russia hopes to create by 2012.