It is obvious that English has its origin in Britain. It started out as one of low-profile European languages. As the British Empire prospered, English also spread across the world. It has been spoken as one of the official languages in the former British colonies since then. After Britain had lost its power, the United States overtook the dominance over the world. Even though there's signs of American power decreasing, US is still the world's most influential nation in terms of technology and international regulations.
Historically speaking, British people used to be Caucasian people with their distinct culture. However, the characteristic has got blurred because of the large scale introduction of immigrants from the rest of the world. US began its history as British colonies. Even after its independence, US was a country where white people are dominant for many years. But now Caucasians are increasingly becoming a minority - its population has been largely replaced by people other than Caucasians such as Hispanics, Asians and Africans.
Therefore, we have to be aware of the fact that, even though Britain and US are still the leading countries in the English speaking world, many members consisting of them are no longer traditional "white" people. English is becoming a global language, which is now spoken by many different people with different backgrounds.
Usually a language is spoken in a certain cultural context. English is not an exception. English is still strongly associated with the cultures of Britain and US. As a Japanese person, I find some difficulty in accepting certain aspects of the British or American culture. Probably, if English wishes to be a truly global language, it should be more culturally neutral. Or it should be tailored to the situations of each region where it is spoken. For example, English should be customized to accommodate the needs of Japanese people when it is spoken in Japan. New vocabulary and expressions should be added to English depending on the English users' demand.
It's important for us to have a recognition that English is not "theirs" but "ours". Although I am not a native English speaker, I am still entitled to use it to convey my ideas to the people across the world. In order to keep it possible to communicate with many different people, I should use a standard English. However, the standard English itself should be determined by the needs of all the people in the world, but not by only those of the people in the English speaking countries.