Complex sentence: At some point between 1780 and 1804, New Crobuzon entered into a war against the nation of Tesh, and by the end of "The Scar", civil unrest had grown to the point that martial law was necessary to keep the reigning government in power.
Split into simpler sentences: At some point between 1780 and 1804, New Crobuzon entered into a war against the nation of Tesh. By the end of "The Scar", civil unrest had grown to the point that martial law was necessary to keep the reigning government in power.