"Editor's note: To mark the fifth anniversary of the invasion of Iraq, Slate has asked a number of writers who originally supported the war to answer the question, "Why did we get it wrong?" We have invited contributions from the best-known "liberal hawks," many of whom participated in two previous Slate debates about the war, the first before it began in fall of 2002, the second in early 2004. We will be publishing their responses through the week."
http://www.slate.com/id/2186740/

Hitchens makes some points that most people can't and won't deal with.
And generally makes a good summary of where we are in regard to Iraq.

You should read the article- if you want a clue.