Had to read this for my book club and I have to say if it wasn't for that I may have DNF'd this book. It's definitely a strange read and just becuase the whole thing is written as if the MC is telling th story to some random man in a cafe. 
It's one of those books that you finish reading and are left wondering what you just read. Was any of it real? Is the guy delusional?

I'm not sure i regret reading it but I definitely would not recommend it to someone else.

Personally I reckon the guy went to America and had a good time for a couple of years (uni etc) and then decided he didn't want to be there anymore so became disenfranchised with everything. Then proceeded to essentially sabotage himself (not saying the tension surround 9/11 helped but he certainly didn't handle it well). After returning to Pakistan he taught people of his bad experiences of America.
I think Erica represents his previous love of America which is why he cannot 'find her' in the novel she wrote, becuase he cannot remember the America he loved. Her "disappearance" also coincides with him becoming disenfranchised with America.