The general low efficiency of integration in the post-Soviet space has one obvious exception — the Union State. At the same time, certain problems exist in the Union State. Successfully solving common problems of foreign trade, the parties do not work effectively enough in the direction of cross-border cooperation and cross-border trade. The European experience of cross-border cooperation and trade cannot be fully applied in Russia and Belarus; however, the best practices of Europe have been successfully worked out for a very long time and can be applied within the framework of the Union State. The special status of the border between Russia and Belarus has some similarities with the formal borders of the EU. Accordingly, cross-border trade can be proposed as a means of developing adjacent areas.