This article gives a good historical overview of the underlying causes of the attacks and makes a case for the theory that government elements ignored warnings of possible attacks on purpose and did not respond on 9/11 as quickly as they could have.
http://www.wsws.org/articles/2004/mar2004/comm-m25.shtmlExcerpts:
“The public hearings conducted Tuesday and Wednesday . . . made clear that the bipartisan panel is engaged in a cover-up of the fundamental questions surrounding the September 11, 2001 terrorist attacks”
“The 9/11 commission’s failure to consider the historical and political context of September 11 goes hand in hand with its refusal to seriously examine the staggering and unexplained anomalies that surround both the preceding period and the events of that day.”
“Within the context of the preceding history and the political exploitation of September 11, the mysteries of that day find their most plausible explanation in a deliberate decision by elements within the US government and military-intelligence apparatus to allow a terrorist attack to take place”