The government last week successfully blocked the publication of the name of an MI5 spy who had Nazi materials and used his status to terrorise his partner. The BBC has a video showing the man threatening to kill the woman and attacking her with a machete. It also says, “Evidence shows that he is a right wing extremist with a violent past.” Beth, a British national, met the agent on a dating site. The couple went on to live together in Britain. Beth—not her real name—says he sexually assaulted her, and was abusive and coercive. She says he used his...