I have always seen the invasion of Afghanistan completely differently than the invasion of Iraq.  The Taliban regime was supporting terrorists, and did have direct links with Bin Laden and the 9/11 attacks.  I think that overthrowing their regime was a legitimate and necessary response to 9/11; I am only sorry that the invasion was left half finished.  We let Bin Laden get away, and we have failed in the task of rebuilding the country; in fact, it is falling back under the control of warlords.  

Here is a question for John in Norway: if NATO is not willing to respond to direct attacks on its members, then why does it exist?

IMHO, the US should have invited broader NATO participation in Afghanistan 3 years ago, then maybe the country would have developed in a way that we could all be proud of.  Finally, I would like to note that I have always opposed the invasion of Iraq, and I am mortified by the use of torture.  But the world is full of bad people, and sometimes they can only be stopped by force.