This chapter analyses the diffusion of party politics by focusing on the ideological shifts within political parties in Central and Eastern Europe (CEE) and analysing the impact international diffusion has on these shifts. It presents an overview of the handful of studies that analyse the impact of international factors on party positions. The chapter then outlines a model for the analysis of shifts in party positions that integrates aspects of domestic politics and international diffusion. It uses party positions, policy positions, programmatic positions and ideology interchangeably. The chapter also examines whether the European Union (EU) countries exercise diffusional power over the Baltic states. The Baltic states often emphasize their commonality with the Nordic states. Finally, the chapter aims to develop a model for the analysis of ideological shifts of political parties that includes domestic as well as international and diffusional variables.