Hydraulic despotism - Wikipedia
Hydraulic despotism is a term for despotic rule supported by control of a single, necessary resource. The term was coined by the German theorist Karl A. Wittfogel in his work, Oriental Despotism in 1957. In its original instances, it was literally water that was controlled - in Ancient Egypt and Babylonia, (as by extension, Wittfogel argued, the contemporary Soviet Union and People's Republic of China) the government controlled the irrigation channels. Good, loyal subjects received plentiful water for their crops, while less-loyal "bad" subjects were starved of water so that they and their crops died. The term can be used to indicate any tyrannical rule propped up by control of a vital resource. Whether this term can apply to a (near-)monopoly on something more esoteric, for example technology development, is debatable.
In fiction
Frank Herbert's Dune establishes a universe centered on a hydraulic despotism: The spice, Melange, is essential for, among other things, space travel; it is said that "He who controls the spice controls the universe".
In the film Total Recall, the air on Mars is controlled by a central authority, which acts as a hydraulic despot.