I'm sorry for probably sounding stupid, but I wonder if anyone knows why we're being terrorised. I see/hear/read loads about attacking and trying to defeat terrorists, or defending against them but I don't see anything about why they are terrorising us.
If this has already been debated please link me to the thread, so I can understand why we spend so much time and money and forgo so many of our liberties and freedoms in this struggle.
That is a good question worthy more than a simple one liner glib response.
If our goal is to reduce the risk of a terrorist attack, then it is logical to examine what motivates them to 1) be terrorists, and 2) attack us. The goal is not to blame America, but to determine why they do what they do to determine how to undermine it. And anyone who things that the actions of one nation cannot have a conquenence is either a fool or has purposely has their head up their ass.
"Terrorism" is not at heart the problem. Terrorism is a tactic used to achieve goals by a group that doesn't have the resources to have an army and bombers and jets. The real heart of the problem are that people that are willing to engage in terrorist tactics (often requiring kamikazee type suicidal missions).
Unfortunately, this is a complex question. You are not dealing with one person here. We can look at what bin Laden says for some insight on his thinking, but terrorists, and potential terrorists, is not a homogeneous group and like any large group you can expect that many different people have different motivations for different things.
But lets start wth Bin Laden since he is the head, at least figuratively, of AQ. If you study his background, his initial beef was not with the US or even Israel, but with the Saudi Govt. Bin Laden came from a wealthy Saudi family, but because disenchanted with the Saudi government, believing they were corrupt (and he's probably correct). Bin Laden determined that the Saudi Govt had to be overthrown. This got him in hot water with the Saudi Govt, which expelled him.
Bin Laden then turned his ire on the US, particularly after US troops were in Saudi Arabia, and he viewed US dollars and troops as upholding the corrupt Saudi regime. It was about this time when Bin Laden was in Afghanistan in 1996 he issued his fatwa against the US. If believed that if unless he could get the US out of the ME, he could not accomplish his goal of overthrowing the corrupt regimes in places like Saudi Arabia.
Lots of other terrorists (particularly in Palestine) are more motivated by the Israel situation, particularly those in the ME vicitinity. Israel has been a handy vicitimization card of Muslim regimes for a while, and US support of Israel has certainly inflamed anti-US feelings among Muslims. This is particularly true when the US has been viewed as having a very hard line pro-Israel government, like the Bush administration.
The ME is characterized by corrupt governments, and vast disparaty in wealth between the haves and subsistence level existence for everyone else. Any time you have a situation of extreme poverty and despair you have the opportunity for greater support for radicalism.
There is the colonial history of the ME. The arabs are a proud people, who had endured centuries of domination by Christian European powers. That makes them particularly hostile to perception that Western countries (like the US, even though it wasn't a colonial power) are trying to overrun and change their culture.
Finally, in more recent years, there was the US invasion of Iraq, which was perceived to have been unjustified as it was premised on WMDs that Iraq didn't have. The raised perceptions that the US is working as a surrogate for Israel and is trying to dominate their holy land and culture. A number of terrorist groups sprang up in Iraq after the invasion.
There is the religious aspect -- Islam has many tenants that say you should resist against those who attack you. A particularly violent and radical strain of Islam -- Whabbism -- comes from Saudi Arabia and its spread has been funded by the huge about of petrodollars that nation receives.
There are many causes that motivate anti-American hatred that fuels terrorism. This is just some of the more major ones. A true effort to reduce terrorism would involve consideration of these (and other) factors to determine where we can positively influence them.