"To address its security challenges, the United States needs the active support of its allies. This means, in particular, ensuring that the states of the North Atlantic Treaty Organization (NATO) remain able and willing to make a contribution to resolving their common security problems wherever possible. The revision of NATO's strategic concept offers an excellent opportunity to further this aim. It is a chance to build consensus about the future and thereby steer the alliance in a direction that will help keep it relevant. This paper examines five possible directions--refocus on Europe, new focus on the greater Middle East, focus on fragile states, focus on nonstate threats, and a global alliance of liberal democracies--the alliance might adopt, assessing them against certain key political and military criteria. It offers those involved in the rewrite both a range of potential options and a preliminary assessment of the feasibility and potential implications of each. The purpose is to encourage debate around the major, concrete problems that member states face."--RAND web site.