People _hate_ for many reasons. But trying to figure out why someone _hates_ you has little chance of actually solving any sort of problem.
As ikendu noted above 'People don't plan for years, spend tons of money and get an entire group of men to separately and deliberately commit suicide while killing thousands of other people they don't even know... without some compelling reason.' But there is an implied logical fallacy here: the compelling reason need only be compelling _to them_. It is _useless_ to change oneself on the basis of others _hatred_ for you. At the _best_ you will earn disinterest. At the worst you will simply be seen as weak and earn even more _hatred_.
This is not to say that the United States is perfect, and that we shouldn't change our actions. It is simply to say that any changes should be based upon our own reflection, and our _listening_ to the various complaints about us, and especially by _listening_ to what are allies say, especially when they disagree with us. Not that we should do what they say; just that we should listen and understand. And when we change, we should change for positive reasons and to be better friends with those people who would be our friends. We should _never_ change to appease those who hate us.
After 9/11, I heard many people pointing to their pet peeve with the US as the _Cause_, saying that if we'd just change our ways, 9/11 wouldn't happen again. Variously I was told that I needed to use less foreign oil, stop supporting Israel, stop supporting non-democratic Arab governments, stop supporting capitalism, stop supporting gay rights, stop supporting pacifism. The point is that hate can spring up for _any_ reason, based on your most evil and wrong actions, or based upon your most righteous actions.
The United States is often seen by the rest of the world as being arrogant. This earns us a considerable amount of anger, eg in France and Germany. But anger and hatred are two _very_ different things. This anger means that we are doing less work for our mutual benefit...but it will pass, because we do share so much with are European Allies. Also, this anger gives those who already hate us an excuse. But IMHO it is not a significant _cause_ of hatred.
Our current actions in Iraq and Afghanistan, IMHO, _will_ lead to greater terrorist activity, but _not_ because they will generate hatred. They will lead to greater terrorist activity because we are not going far enough fast enough to rebuild the infrastructure and civil society in these areas. _Not_ because the lack of infrastructure is generating hate (it is generating anger), but because the lack of infrastructure and lack of civil society is providing fertile ground where the the already extant hate can hide and grow.
Al Queda was not in Afghanistan because it is composed of Afghanis; it was there because it could hide. Al Queda exists where it can hide easily, and to some very considerable extent we have opened up Iraq to it. Now we have to re-close Iraq, and not by putting millions of American troops there, but by helping our friends on the ground rebuild their lives so that _they_ will want Al Queda _out_.
Back to the central point: trying to figure out why we are hated will do us no good. We have to focus on building and doing good, on evaluating (and correcting) our own actions, on listening to our friends and allies. We should do right _despite_ terrorism, not because of it.
-Jon
(P.S. By do right _despite_ terrorism, I mean doing things because they are the right things to do, _even_ if they are things that the terrorists want. We should _ignore_ the demands of terrorists, and act only based on what those who will work _with_ us (even if we often disagree) ask and demand of us.)