Managing NATO Enlargement
https://www.usip.org/publications/1997/04/managing-nato-enlargement
On March 5, 1997, the United States Institute of Peace convened the first session of its European Security Working Group to discuss the implications of the North Atlantic Treaty Organization's (NATO's) commitment to enlarge the alliance at the July 1997 Summit in Madrid.
Dr. Zbigniew Brzezinski assumed in his remarks that the decision to enlarge NATO will be made at the Madrid Summit and offered insights into current thinking on this issue in Russia, Europe and the United States. He also suggested ways to enlarge the alliance and build a relationship with Russia without sacrificing the interests of Central and East Europeans or NATO's ability to fulfill its purpose and missions.