This research provides an interdisciplinary and contextual study on the phenomenon of English promotion at the turn of the 21st century. Through documentary research and semi-structured interviews, it examines the politico-economic and socio-cultural dimensions of English promotion in the context of East Asian countries, including China, Japan, South Korea and Taiwan. It is suggested that in East Asian societies where economic development, education, and cultivation of manpower are emphasized, English as an acquirable competence is given high socio-cultural value due to its strong association with economic well-being. English is considered the resolution of national competitiveness and a prerequisite of individual economic achievement, and it not only leads to a series of economics-driven language and education policies but also boosts the economy of English-related industries in these non-English-speaking East Asian countries. Overall, English promotion in East Asia is an economics-and-politics-driven, self-justifying mechanism which illustrates how the value of English and the social and individual investment on English teaching and learning are legitimated and how English as commodity is marketed through a synthesis of discourses, presuppositions, and national policies.