There no monopoly on the lessons of history
Just to balance the argument up a bit. A couple of other lessons of modern history.
Firstly, I recall visiting Bergen-Belsen Memorial a few years back and above an exhibit of photos is a quote along the lines of.."first they burn the books, next they burn the bodies.." What lessons can we learn from this dramatic, if not most dramatic, event of modern history? You may recall the Taleban was keen on book burning, religious monument destruction, persecution of minorities....
Secondly, perhaps there was merit in the idea of leaving the Taleban alone; out of sight, out of mind. However, the Taleban allowed, alternatively, actively encouraged, the establishment of Terrorist Training camps within its borders. We now know that persons trained at these camps had direct involvement in 911, perhaps the most dramatic event of the passed 10 years. Were the Taleban ever out of sight, out of mind??? Would they have been content to leave it at 911 or would they have moved on to even bigger and better things??
I am not saying the campaign in Afganistan has been a huge success, however what I am saying is there are many lessons in history and anyone can quote any lesson to support any argument