Chatham House, the London foreign-affairs think tank, has given its seal of respectability to the claim that Britain's participation in the liberation of Iraq allowed al Qaeda to transform a bunch of ordinary Muslim youths into the suicide-killers of July 7. ...[I]t is not clear how anyone could know that the suicide-killers were solely motivated by Britain's role in Iraq. The two claims of responsibility for the operation cite a variety of reasons, making it clear that the attack on Britain was part of a broader campaign against the "infidel" West. And how could Islamist suicide-bombers be concerned only about...