In a constructivist perspective, NATO and the EU are community organizations. Consequently, the first step in the sociological institutionalist analysis of their enlargement is to determine the community culture. I claim that NATO and the EU are regional organizations of the Western international community. The members of this community share a liberal political culture – a postnational identity based on liberal norms of domestic and international conduct. Moreover, both NATO and the EU pursue a moderately exclusive strategy of international socialization that entitles outsider states to become full members only on the condition of advanced internalization. The second step in the analysis consists in showing that NATO and the EU decided to admit the (most) successfully socialized CEECs, indeed.

The Western international community

Both NATO and the EU are organizations of the Western international community which is characterized by three core features. It is an interstate, liberal, and postnational community.

The Western international community is an interstate community. States have established and further developed the community organizations through international treaties. Only states can become members, and it is states that decide whether or not an outsider state is admitted. Moreover, the size or power of political entities is not a criterion for membership as long as these entities qualify as states. States with well below one million inhabitants such as Luxembourg are members of the community; substate regions, let alone cities, with well above that population are not.