Efforts to be made
The best thing to deal with the situation of co-existence, or competition, of American English and British English would be some kind of harmonization. This solution, which suggests changing the natural course of a language or language variety, had hardly been succeeded. The other question is even if this solution were possible, the harmonization in the direction of American English are demographic, technological, political, commercial, and media-related, as analyzed above; in fact, most predictions, including that of David Crystal, are that English in future will be American-dominated. Arguments for harmonization in the direction of British English include the fact that the majority of dictionaries and English Language Teaching materials outside the US are British English–dominated. The other argument is of an emotional and symbolic feeling and mixed with the sense that British English is after all the mother variety.
Modiano's solution to the exposure to, and mixing of, American English and British English is that Mid-Atlantic, spoken in increasing numbers by Europeans. Should replace British English as the educational standard in Europe. According to the author of “The Americanization of Euro-English”, Mid-Atlantic is “a variety that encourages neutral pronunciation and a vocabulary based on the interlocutor's frame of reference'. The only problem in Modiano's argument is that he carefully explains the reasons for Mid-Atlantic English to be used, and what does not constitute Mid-Atlantic, but fails to discuss in concrete terms some detailed characteristics of this variety
For lacking in a guaranteed solution to the problem, I suggested that courses in contrastive analysis of American English and British English should be widely included in English Lessons to wipe out the confusion of those who learn English as a second language.