Hutchinson and Waters (1987) note that two key historical periods breathed life into ESP. First, the end of the Second World War brought with it an " ... age of enormous and unprecedented expansion in scientific, technical and economic activity on an international scale · for various reasons, most notably the economic power of the United States in the post-war world, the role [of international language] fell to English" (p. 6). Second, the Oil Crisis of the early 1970s resulted in Western money and knowledge flowing into the oil-rich countries. The language of this knowledge became English.