7/7, a perpetratorless crime

Reading about today's national memorial service for the victims of 7/7, I can't get over how passive Londoners (and Britons for that matter) have been in their reaction to the terrorist attack on their city. Contrast that with 9/11 where in the weeks that followed, the reaction of most Americans was: "Who was responsible for this? And what's their address so we can bomb the hell out of them!"

One often hears about so called "victimless crimes," remember when George Michael was arrested when his potential cottaging partner turned out to be a plainclothes police officer? There were some who objected to his prosecution because there was no apparent victim. Well if there can be such a thing, I would like to suggest that 7/7 has become a "perpetratorless crime", Four months later, we still can't decide who was to blame:

Suspect 1: Were the bombers responsible? No, they were young impressionable men who were indoctrinated by their handlers. At one point, London's Mayor and even the Church was insensitive enough to suggest the bombers families could attend the memorial services.
Suspect 2: Ok, so were their handlers responsible? Well....kind of, BUT you have to understand, they were driven to do this by their anger at what is happening in Iraq, Palestine, Kashmir, etc..

Ok, you get the idea. In fact, Britain's reaction over the last few months has resembled a game of Cluedo rather than a war on terror.

Having a memorial service, celebrating the lives of the victims, and making noble statements such as "London stands united" is all well and good, but what are we going to do to prevent this happening again? It seems we haven't given much thought to this question.