Saturday marks the third anniversary of the murder of journalist Jamal Khashoggi, who contributed columns to The Post. It is a good moment to reflect on the duty to speak out against authoritarian rule. Our late colleague wrote on Sept. 18, 2017, that he hadn’t protested initially when some friends in Saudi Arabia were wrongly arrested, but then decided he must. “I am raising my voice. To do otherwise would betray those who languish in prison. I can speak when so many cannot.” For his principled stand, Khashoggi was drugged and dismembered by a Saudi hit squad.