One of the top U.S. experts on NATO enlargement speaks to TOL about the alliance's democratizing power, the challenges facing new invitees, and NATO's future role. You have reached a premium content area of TOL. To read this entire article please login if you are already a TOL subscriber. Not a subscriber? Subscribe today for access to: Full access to the website, including premium articles videos, country reports and searchable archives (containing over 25,000 articles). You can subscribe here to gain access to the entire website.