I agree with all of that, apart from your last conclusion. The British intelligence service was, it appears, acting logically given its motivations and capabil

I agree with all of that, apart from your last conclusion. The British intelligence service was, it appears, acting logically given its motivations and capabilities. It achieved the outcome it wanted. Note that the motivations do not always align with what is good for Britain (nor, rather obviously, other countries) - see e.g. Iraq intelligence. From what is visible (e.g. Snowden data), GCHQ continues to do the same thing. But it has vastly greater capabilities, both in collection and analysis. This means we have been heading towards an ever more capable/powerful surveillance state.