He guarded Ismail Haniyeh for Hamas. Britain gave him asylum, then a passport. Now German prosecutors say Mr X, as the courts call him, was involved in an alleged plot to attack Jewish community centres, Israeli diplomats and pro-Israel rallies in Europe, timed for the second anniversary of October 7. A judge granted him anonymity for 100 years. It took a newspaper query to fix that. The allegation facing Mr X is extraordinary. The unanswered question for Britain is how much of his past was known, and by whom, before the state gave him its protection and, eventually, its passport.