Widening and Deepening: Reforming the European Union
分析欧盟如何通过核心国家威胁组建“俱乐部中的俱乐部”来推动一体化，以及不同成员国对一体化速度和深度的分歧如何影响改革进程。
The European Union is the product of a unique institutional process: individual states, often with a history of belligerent relationships, have gradually given up ever more sovereignty to produce an increasing number of common goods, including the Single Market, a joint currency and common policies. In the process, the Union has integrated increasingly diverse countries and achieved institutional progress beyond its borders. These achievements are particularly remarkable given that member states have had and still have widely different views of the desirable speed and ultimate depth of integration. Possibly the single most powerful force sustaining the process of integration has been the implicit, and often explicit, threat by more committed member states to form an inner core, a “club-in-the-club”. Conversely, less enthusiastic members have supported extending membership to more countries as a strategy to