La sécurité en Europe centrale et orientale un système en cours de changement

The end of the Cold War concluded a period of clear division of Europe into east and west, each closely tied for security and other purposes to the Soviet Union or the United States. The collapse of the Warsaw Pact and the scramble of its former members to enter into Western organizational structures called into question the very definition of "Europe". The Western response has been a commitment to enlargement eastward of both NATO and the European Union, as a means of extending the "zone of peace" into Central and Southeastern Europe, among other objectives. Russia's concerns and opposition to NATO expansion were largely ignored by Washington and its allies. Since the terrorist attacks in the United States of September 2001, Russia under President Putin has muted its concerns and pursued a policy of collaboration with the United States and Western Europe.