Imperialism (/ɪmpɪərɪəlɪzm/) is policy or ideology of extending a nation's rule over foreign nations, often by military force or by gaining political and economic control of other areas. In recent times, it has been considered morally reprehensible and the term is used in international propaganda to denounce an opponent's foreign policy.
English has become a major world language because of imperialism - first of the British and subsequently the Americans. Linguistic imperialism is a type of imperialism. English language teachers would do well to note sensitivities in this area, which is often criticised as part of critical theory.
See also: globalisation.