"One of the key issues in the debate on NATO enlargement is the question of NATO's purpose and mission. This analysis suggests some possible answers to the question 'What is NATO?' The answers are based on an interpretation of the North Atlantic Treaty, the observation that an organization is defined by its activities, and the declared objectives and intentions of its members. From this view, NATO clearly remains a collective defense pact in which the members pledge to take steps to assist another member that comes under attack. But under current threat circumstances that commitment no longer dominates NATO's day-to-day agenda. The Treaty also suggests that NATO is a community of values and common goals in support of 'democracy, individual liberty and the rule of law,' which may help explain why NATO has survived the end of the Cold War. Today, the members have moved beyond the collective defense commitment to employ NATO's strengths as a defense cooperation organization for additional purposes. These purposes include creating political/military options for dealing with crises and challenges to the interests of the member states, spreading stability to Central and Eastern Europe, and encouraging cooperation with Russia and other countries. NATO is not a system of collective security, because it is not designed to resolve disputes among its members, but its activities contribute to collective security and make it a key part of an emerging Euro-Atlantic system of cooperative security."
CRS Report for Congress, 97-708