The three key ingredients in attack are : Vulnerability, opportunity and motive. should you have physical vulnerabilies explain how you would go about to harden yourself as a target of terrorism.
The most effective defense against terrorist attack, in my opinion, is a more progressive foreign policy. Deny terrorist groups the economic environment which makes recruiting easier for them. It is virtually impossible to protect every soft target against any terrorist attack, and yet still remain a free society. It makes more sense from almost every angle to pursue policies and programs which remove the motivation and opportunity for terrorist groups to recruit, fundraise, organize and to execute attacks.
One point that was not mentioned so far is the importance of firming up borders. It is important to have good border patrol and good intelligence mechanisms in place at airports. Also it is important to check cargo that is shipped to America. All of this is tedious work, but important in protecting the nation against terrorism.
Continuing the thoughts of the last post - for those who have to fly, the process of beginning that trip has changed radically with the institution of increasingly refined screening practices. Security checks of persons who will be boarding airplanes and the luggage they will be taking with them or checking into cargo areas have been created in an attempt to make those in the air less vulnerable to acts of terrorism.
Obviously, this gets into the debate of "when is trying to keep us safe and secure more important than recognizing individual rights and personal privacy?", which is not the point of this post.
I really don't believe there is much an individual can do to avoid being the target of a terrorist attack. Living in fear of such a possibility is no answer, and trying to avoid large crowds and important events only microscopically reduce the possibility of involvement. Avoiding flying may be a simple answer for people who don't travel much, but for business purposes this is also not a solution.
As mentioned above, one cannot isolate oneself from the dangers that lurk. It is important not to live in fear. Take every precaution, but do not live in fear. One can only hope and "pray" for safety. I do feel that the government is taking every precaution and just being aware of danger is a great way to be safer. Natural instinct is a great precautionary measure. If it appears dangerous, it probably is.
The ideas expressed above cover a lot of ground and bring up the most pertintent points that come to mind for me...
As individuals, there is not much anyone can do to make possible targets safer. It is up to security agencies, either state or local, to control traffic, limit access, and provide some modicum of screening in the places that seem most vulnerable to attack.
Beyond the metal detectors used at almost all potential target zones, watchful eyes are probably the best way to decrease vulnerability.
In Washington DC and most state capitols, many government facilities are now surrounded by concrete barriers that keep potential car bombers from getting too close to the building. Beyond measures such as these, and the increased scrutiny alluded to in the previous post, I agree that there is little that can be done. Part of this is due to the inherently responsive nature of anti-terrorism- we cannot counter what we cannot imagine will happen, and terrorists have proven stunningly imaginative in their methods of attack. But there is also the element of logistics- at what point do security measures get in the way of the use of facilities?
I assume that you are talking about countries or communities rather than us as individuals. There is very little any of us can do to "harden" our homes or our persons against terrorist attack. As a country or a community, all you can do is to assess your greatest weaknesses (the targets that could do the most damage) and to try to improve security around those targets. Near my community, for example, one thing that has been done is to increase scrutiny of people wanting to visit a major dam in our area.