I think most of us really see these issues through our own lenses only. We don't see how our nations fighting in Afghanistan, etc and in the process end up killing innocents is helping fuel incidents like this in the UK, France, etc.
Watching the quite interesting shows on the US killing of Bin Laden this past few days.
I wonder what the reaction would be if Pakistan knowing some enemy of theirs was holed up in some place in the Catskills and they came onto US soil with a team of crack commandos - did the dirty deed and escaped without being apprehended. Improbable given the geography of the USA and North America but there would be outrage.
Now how does Pakistan really feel about the US incursion by the US in their country and these guys have nukes. How much of an impact does that have on radicalizing more of these idiots.
As the say one man's terrorist is another guy's freedom fighter.
The sooner the west ends the war on terror the sooner they get to fight and create new enemies. Obama's trying as he wants to shift to Asia and of course they are broke now fighting in that region.
This stuff in the UK hinders the US pivot to Asia Pacific.
http://www.fas.org/sgp/crs/natsec/R42448.pdf
Then there was the contribution that the Afghan War made to the collapse of the USSR that weakened the main pillars of the USSR - the Communist, Party, KGB and the military. When the annexed countries saw the Afghans kicking their butts they got bolder and bolder.
http://faculty.washington.edu/aseem/afganwar.pdf
I think the lessons here are that more war on terror is going to bring these issues of beheadings, etc back home as these self radicalizing morons take dumb actions like this.