There is not a great deal I can add to what has already been written about this sorry business but, since I am working on a new course of lectures on ‘Diplomacy and Secret Intelligence’, it has pricked my interest. I shall, therefore, at least say this:
(1) I agree that it is highly likely that the Russian government was, in one way or another, culpable for the nerve agent attack in Salisbury.
(2) It is naïve to expect the fully available proof of this to be revealed since this would probably compromise sources; as also is it naïve to demand that governments remain inert until they have the standard of proof required by a court of law.
(3) I believe it to have been a mistake to retaliate by expelling Russian intelligence officers operating under diplomatic cover; first, because they probably had nothing to do with the nerve agent attack, either directly or indirectly; and second, because loss of secret intelligence increases ignorance, ignorance breeds fear, and fear increases the likelihood of impulsive actions.
(3) The Russian intelligence officers were described as ‘undeclared’, as if this were somehow typical of a particularly wicked government. But this is gratuitous language since all intelligence officers based in embassies and consulates pretend to be diplomats or consuls. It is only intelligence officers in diplomatic and consular missions to friendly states who are ‘declared’, and then only discreetly to their counterpart ‘liaison’ intelligence services. In spook-speak, the expelled Russian intelligence officers were simply ‘legals’, using their true names under diplomatic cover just like the British intelligence officers based in Britain’s Moscow embassy. (‘Illegals’ are the rarer breed of intelligence officers who are given false identities and operate as businessmen, journalists, and so on.)
(4) The British government claimed a triumph for its diplomacy in lining up so many other countries to follow it in expelling Russian intelligence officers. But this was almost certainly the product chiefly of the long-established excellent relations between Western intelligence services, with the Foreign Office playing no more than a supporting role. It also further exposed more than one ominous fault line in NATO: Turkey.