The chapter first deals with the effects of the completion of the single market and with the debate opened among the European foreign ministers in the framework of the mechanism called European Political Cooperation (EPC). It concerns the issue of "consistency", or, in other words, the increasing recourse made by EPC to European Cooperation (EC) instruments (and vice-versa) as sanctions or the use of conditionality in economic assistance, in order to further its policies, as shown by the case of Poland. Then, the chapter focuses on the relationship between the EC and the Soviet Union. Through this focus, it demonstrates if and how the completion of the single market and the revival of European integration in the second half of the 1980s affected Mikhail Gorbachev's diplomatic concept of a European Common Home and how this project was perceived by the European governments.