Trust Building, Trust Breaking: The Dilemma of NATO Enlargement

Barbara Koremenos, Charles Lipson, and Duncan Snidal conjecture that the conditions of membership in international institutions will grow more restrictive as a response to uncertainty about state preferences. Membership criteria will act as a signaling device—states more committed to cooperation will be willing to meet the criteria, whereas those less committed to cooperation will not. The recent enlargement of NATO to include the former Warsaw Pact members Poland, Hungary, and the Czech Republic illustrates this logic. The potential candidates for admission had to meet standards with respect to democratization, civilian control over the military, and the resolution of border and ethnic disputes with neighbors. These criteria served to identify the more cooperative potential members and to encourage cooperative behavior among those who aspired to membership. However, NATO enlargement came at a price. Although trust was built and cooperation fostered between the East European states that gained membership, trust was broken and cooperation harmed between NATO and Russia. This unfortunate outcome represents a dilemma that arises in the expansion of a security community: While expanding the security community enlarges the zone of peace and mutual trust, it may generate fear among those still on the outside, who view it as a potentially hostile alliance. I present a game-theoretic analysis of this dilemma and analyze the conditions under which it arises.