In her book Precarious Life, Judith Butler reflects on the reactions to 9/11 and explores the question of the different valence of life. The book offers a theoretical examination of grief, violence, and the link to privilege and global power relations.
Judith Butler 2004: Precarious Life. The Powers of Mourning and Violence. New York: verso.
If you don’t have a bookstore worth supporting near you, you can also buy the book from the alternative non-profit online bookstore links-lesen.de, which supports political projects with the profits. The link to the book is: http://www.links-lesen.de/article/1-84467-544-0