The realisation that former Russian spy Sergei Skripal had been targeted with a nerve agent in the English city of Salisbury sent shockwaves through the world of British spies and raised important but difficult questions, writes security analyst Gordon Corera. Some were answered by a report published on Thursday, which held Russian President Vladimir Putin "morally responsible" for the death from Novichok of British woman Dawn Sturgess. Today, Russia, its spies and its proxies are engaged in a low-level conflict with the UK and other European countries which involves carrying out acts of surveillance and sabotage, our correspondent notes. Gordon writes that Russia's ability to carry out another nerve agent poisoning is almost certainly diminished, but that does not mean there are not other types of danger.