Am I right in remembering that Silva is supposed to be from the Azores? If so, what (if any) effect would this have on the speculation in this thread?
Well, there's the question of how a Portuguese citizen might have come to work for the British secret service. But considering all the foreigners who have worked with MI6 (Kerim Bey, Vijay, Manuela, and so on), there's nothing strange about that. Portuguese nationality ties in neatly with Macau, so I suspect that Silva's background with MI6 probably involves an operation there.