In the furore over the Richard Gott affair (letters, December 13, 16, 20), insufficient attention has been paid to one significant feature – the inability or unwillingness of the Security Service, MI5, to counter the activities of agents of influence. The Times has done more than most to highlight the difference between two wholly distinct types of KGB agent: the intelligence (or espionage) agent, and the agent of influence. The former were spies passing Western secrets to Moscow, whilst the latter were propagandists feeding Moscow disinformation to the West. Both forms of activity are subversive but, since they are not...