Let me guess, American authorities took down the twin towers with controlled implosions. The airplanes were just holograms?
Us withdrawing into a cocoon is not going to undo the past foreign policy. The past cannot be undone. We must deal with the paradigm we have regardless of the reason for the paradigm.
No the war on terror is very real, and will last decades even if by some fluke Ron Paul is elected President someday.
And Bin Laden is not the entirety of the enemy. It is between 5 ad 10 percent of the Muslim population of the world. Killing or capturing Bin Laden would be nice, but not the end of the war by any stretch.
No matter what we do presently, they are at war with us. We can engage or not. Not engaging will not make us their buddies.