This article explores the nature of the member-state building process that has taken place in the past decade in Central and South Eastern Europe. It notes the importance of the Helsinki European Council decision in 1999 to treat all candidate countries within a single framework, and highlights how this has led to parallel transformations of the political landscape in Romania, Bulgaria and Turkey. In all three countries opponents of reforms associated with EU membership were marginalised and a broad social and political consensus emerged that transformed domestic politics. However, in the case of Turkey the focus of member-state building has until now been largely on the political criteria for membership. As Turkey prepares for real negotiations in the wake of the December 2004 decision, issues of economic and social cohesion, which have been central in the case of all other candidates until now are coming to the fore. The issue of Turkey’s internal lack of cohesion will become a central issue in the adoption of the acquis, and will likely become the focus of the member-state building effort in the coming decade. It was therefore crucial that the negotiations with Turkey will be similar to those with all previous candidates, and that cohesion will also be a central concern for the EU itself, something that proponents of schemes for a “privileged partnership” had unsuccessfully opposed. One crucial issue will be whether the Turkish state is able and willing to undertake the vast administrative and policy reforms required for an effective regional policy in the near future.