Last Friday, the day before voters in Mauritania went to the polls for parliamentary, regional and local elections, United Nations Secretary-General Antonio Guterres said in a statement that he would be “closely following developments” in the West African country. In particular, he called on “all parties” to “allow for the participation of all interested stakeholders.”

By that point, however, this wish was already out of reach. That’s because in early August, Biram Dah Abeid, a prominent opposition politician, was arrested at his home by police officers who reportedly said they were executing “an order that came from above.” Abeid remains behind bars, meaning he was unable to actively participate in his bid for a parliamentary seat. ...