I'm pretty sure we weren't attacked because of our "freedoms" and they wanted us to be like them.
They're attacking us because we want THEM to be like US. They're happy in their country, we should leave them alone. We've been over in that area maliciously LONG before 9/11...they hate us because of our international policies and relations.
WE are the ones who need to change that.
I am not sure which people you mean by "they," Playainda, but the context suggests that you mean at least to include those who planned and executed the 9/11 attacks.
To say that Islamist terrorists and their supporters and well-wishers are "happy in their country" is absurd. The terrorists are absolutely NOT "happy" under the existing governments of Saudi Arabia or Egypt or Pakistan or Morocco or Afghanistan: they would bring those governments down if they could, and are constantly doing what they can, very bloodily, toward that end.
It is true that the Islamists hate the United States for supporting Israel and for maintaining a military presence in Arab countries, among other things. But they also hate us for supporting secular governments in Muslim countries such as Egypt and Saudi Arabia. To suggest that if we just let them alone they would leave us alone is preposterous — unless perhaps your idea of letting them alone includes withdrawing all support for Israel, Egypt, Saudi Arabia, Pakistan, Afghanistan, and so on.
If they could overthrow all secular governments in Muslim countries, destroy the state of Israel, and re-establish the Muslim Caliphate throughout the Mideast, southern Asia, northern Africa, and Europe — which I believe is among the declared goals of Al-Qaeda — then indeed they might "leave us alone." And alone we would be, too.