My .02 cents (because I'm staying with my wife and baby at the hospital and won't be around to post for the next 20 pages or so):
I'm not going to bash the United States of America, thank you.
But there is some truth to what MrktMrkt and what the other guys are saying.
Terrorism is, given, a complex issue, with many reasons and sources. The Islamic form of terrorism is only one of the more extreme examples. A discussion of "suicide bombers" ONLY would merely lead to a circular argument condemning only fundamentalist Islamic terrorists and guerillas. This ignores the fact that there are non-Islamic "Communist" terrorists as well as Catholics (IRA, anyone?).
Terrorism is deeply rooted in a clash of cultures, poverty and perceived oppression. In the case of Islamic terrorists, many of those roots are deep in the past, and some of them are still raw. It's a given that Westerners HAVE abused and attacked Arabs in the past, and that there are animosities between Christians/Jews and Arabs that go back centuries.
That said, the US Government and the CIA have, over the past few decades, given the Fundamentalists much to grumble about. The cavalier attitude of the CIA in overthrowing foreign governments and leaders in order to "protect" American interests during the Cold War not only fueled unrest in the Middle East, it created some of our worst enemies. Osama's mujaheddin supporters were once trained and supplied by the CIA in order to harrass the Russians. The CIA practically wrote the book on terrorist attacks by teaching them guerilla warfare. The CIA also engineered regime changes in Iran and Iraq. Whether or not terrorism has any justification (and I am of the personal opinion that THERE IS NONE WHATSOEVER), the US has given them many of the weapons that they need.
Part of the complicity is also with the Russians, who worked hard to fuel anti-US sentiment and who also supplied tons of arms and ammunition to small "revolutionary" groups around the world. The ubiquitous AK47, which has become the icon of the guerilla warrior, was handed out freely to aid the "Communist Imperative". The KGB also provided support for terrorist cells in the past, both in terms of money and training.
Islamic fundamentalism plays a strong role in terrorism, but that role could be taken by any religion or belief system at odds with our own. There was a time, not too long ago, when Darwinian Socialists slaughtered Jews. And before that, when Christians burned Negroes, and long before that, when Christians burned Jews and Muslims. As long as the belief system is rigid and unyielding, and as long as it provides a strong spiritual base, it can be made to support anything.
You can't stop suicide bombers, just like you can't stop a twelve year old from picking up a shotgun and going on a killing spree. There will always be fanatics. What you can do is address the social issues underlying the problem, the poverty, the cultural clash and the political rhetoric fueling this centuries old fire (check out what's happening in France)
.........
And lastly, in terms of Iraq... yes, we have brought this upon ourselves. There were no terrorists in Iraq at the start of the war, just a tin-pot dictator trying to hold on to his own. Bringing him down by force from the outside, the US was ignoring history, and it's own previous blunders. Where the CIA has forced regime-change before, only chaos has resulted, as often, another dictator (sometimes worse) steps in to fill the void. Once you remove a very strong dictator, you create a power vacuum that needs to be filled. There will be many who will want to take his place, and be willing to fight for it. And once you've instituted a mechanism for removing one, it can be done over and over again, even for "elected" leaders. Look to Africa, at the succession of oppressive, genocidal military dictatorships that crop up one after the other (and I don't see anyone "freeing" them).
Another case in point: the Philippines. With the aid of massive civil disobedience, the military forced Ferdinand Marcos (another CIA-funded dictator) out of power. His opponent, who supposedly won the previous election, was put in power, but faced some of the same military officers who supported her in coup d'etat after coup d'etat. Her successor was removed by civil unrest also, and our current president is facing the same problem. REMOVING THE LEADER DOES NOT REMOVE THE PROBLEM, it merely ignores the symptoms and to some extent, makes them harder to correct.
"Freeing" Iraq was never the first priority. "Protecting" American Interests was. The sad thing is watching the politicians who once supported the war fervently backpedal and say they want out... now. Why? Because it is harmful for the US to remain in Iraq, politically, economically and socially... but forcing a pull-out before the guerilla-terrorist problem is satisfactorily solved would be a terrible blow for democracy in the Middle East.
And once things go wrong in Baghdad, who's to say that Iran won't try and "liberate" them?