Crim Tartary, or Chersonesos Taurica as it was known in the ancient world, was the old name for the Crimean peninsula in the Black Sea. Its original inhabitants, the Tauri, were said to be brutal and harsh people who were gradually civilized by the Grecian colonies that settled in the area. This idea was reflected by Euripides in his tragedy Iphigenia in Tauris a bloody play in which savage fierceness is, to some extent, tamed by religion.
Thirty years before the events of The Secret Agent, Britain had allied with the Turks of the Ottoman Empire against Russia in the Crimean War. Nevertheless, the Turks were seen as a barbarous race in the nineteenth century. If they would act better than the anarchists, then the anarchists must be very bad.