ABSTRACT
Accession to the European Union (EU), or enlargement as the process is more commonly called, has long been regarded as one of the most important tools of the organization. Accession to the EU is composed of four primary stages: application, screening of the acceding state, multilateral negotiations between the acceding state and the international organization, and finalization of the accession deal by both parties. According to the two-level theory of accession, variation in accession to the EU is the result of factors at both the domestic level of the candidate country and the international level—namely, domestic administrative capacity, domestic public support for accession, and the presence of gatekeepers in the international organization. This chapter illustrates how each of these factors results in different accession outcomes in the context of the EU. It emphasizes the application of the two-level theory of accession to the EU context, focusing in particular on the accessions of the United Kingdom and of Estonia.
