Britain’s latest descent into authoritarianism fits a depressingly familiar pattern. This is how it tends to work: a subversive group is identified by political elites and presented as a danger to the nation, often being additionally labelled as allies or dupes of hostile foreign enemies. An air of national emergency is contrived, with exaggerated, distorted, or simply invented evidence used to justify claims of an imminent threat. The ensuing repressive measures are supposedly to defend the security of both individual citizens and the nation alike.This is what was really going on when…