NATO and Russia conduct first-ever joint military exercises, codenamed 'Vigilant Skies 2011', to improve cooperation to protect passenger flights between NATO member states and Russia and to prevent hijackings such as the September 11 attacks. [http:--www.google.com-hostednews-afp-article-ALeqM5hQF7VtCdR9EUjyWhPLTni1OqWQlg?docId=CNG.a18ed43041c849816c2cfb3ba8d306c9.621 (AFP)] [https:--www.reuters.com-article-2011-06-07-us-russia-nato-exercise-idUSTRE7564T720110607 (Reuters)] [https:--www.npr.org-templates-story-story.php?storyId=137027665 (NPR)]date=August 2019