We are raiding the Guardian Long Read archives to bring you some classic pieces from years past, with new introductions from the authors. This week, from 2020: The unmasking of the Salisbury poisoning suspects by a new digital journalism outfit was an embarrassment for Putin \u2013 and evidence that Russian spies are not what they once were. By Luke Harding. Help support our independent journalism at theguardian.com/longreadpod