Tom Nairn has been the most forceful and original mind to confront, de-mask and anatomise the British state. The perception that Great Britain was a multinational state and not a united nation had never quite been lost over the centuries, but it was Nairn who almost single-handedly hammered this truth into the skull of British intellectuals and campaigners until it became - as it is today -practically uncontested by the political class. NEAL ASCHERSON,...