The theory of the dilemma of simultaneity is empirically based on the transformations of post-socialist states in Central and Eastern Europe. The transformations after the collapse of the socialist bloc were without precedent with regards to breadth and depth. The dilemma of simultaneity consists of three parallel transition processes on three dimensions. The first part of this chapter explores the three dimensions of the transitions: nation building, political transformation, and economic transformation. The second part discusses the three levels of transformation: (1) ethno-national identity and territory, (2) polity, and (3) socio-economic distribution. The third part highlights the complexity and challenges of multidimensional simultaneous transformation processes. The fourth and fifth parts discuss the role of international actors and socio-economic structures on the transitions in Central and Eastern Europe. The chapter concludes with an account of Elster’s and Offe’s critics and their response.