The author explores the genesis and ranges of interstate cooperation within the scope of the Adriatic Charter of Partnership, signed in Tirana on May 2, 2003 by Republic of Albania, Republic of Croatia and FYR of Macedonia, and the United States of America. First three member states of the Adriatic Charter Group have been united in their common objective to become an integral part of the NATO. USA gives strong impetus to member states of the Group to implement all the criteria for the membership in NATO promoting the "Open Door" policy. The author analyses Charter of Partnership and evaluates results of the meetings of the Partnership Commission and other mechanisms for interstate co-operation.