@Drnaline,
Jesus it's like talking to a five year-old.
Osama Bin Laden gave us three reasons for his declaration of jihad against the United States:
1. Bases in Saudi
2. Sanctions on Iraq after Gulf War 1
3. Support of the State of Israel.
He said it, not me. Seems to me that his list of grievances is pretty straight-forward. If we stop meddling overseas, people will not have a reason to attack us (Canada does not suffer international terrorism regularly, if at all, to answer your question). Random acts of violence occur domestically, but terrorism requires planning and dedication not usually spurred by a simple, "we love freedom" rally.
The people who died on 9/11 were innocent victims of a terrorist attack, THEY did not deserve to die. However, America as an entity was and is deserving of counter-hegemonic forces due to its aggressive posture in the region since the 1950's. We need to understand why we were attacked so that we can stop doing that which incites hatred of America abroad. I don't pretend that we can please everybody, because SOME Islamists just generally hate the West (Sayid Kotb for example), but do you seriously think having unnecessary bases in Saudi HELP our case?