Many books that we read in our every day lives originated from other countries and were written, in many cases, in different languages, having been transcribed for us to understand in English. Similarly many English novels are read around the world despite English not necessarily being the reader's first language. The success of these books seems to suggest that literature defies language barriers: to be a bestseller it doesn't matter what language you write the book in, or indeed where you are from. All that matters is your skill as a writer, your deft as a storyteller and the making of a fantastic plot.
Not only does this prove that a book can be written anywhere in any language to be internationally successful, but it also shows that being successful internationally can affect how much the author achieves. International appreciation seems to improve authors' success rate and the way in which we as a reader or critic label authors as successful. For example within children's literature (and many adults enjoy it too!), JK Rowling would be deemed a hugely successful British author. The Harry Potter books definitely make for a fantastic plot and interesting stories, but what makes JK Rowling hugely successful is her recognition worldwide. Harry Potter has been translated into at least 70 languages and is read in at least 74 different countries. Not to mention nationwide success, international success takes readership of books to a new level of achievement and recognition.
Scott Peck and Ann Morgan (both American) made a point of reading books from different countries around the world: Scott Peck read a short story every day for a whole year and Ann Morgan read a book from every UN recognised country. What this proves is that literature transcends language: a book can be enjoyed wherever you are in the world whatever your language, nationality or country. Just because you only speak English doesn't mean that you can't read literature from around the world: so many books are translated and it offers a world of opportunities for learning about different cultures, lifestyles and exploring the world without ever leaving your living room!
How important is it to us that the books are written by english authors or international authors? Does it change our feelings towards the literature? The answer is no. Whilst we have huge national pride when a British author achieves World-wide success, it doesn't affect how we judge or enjoy the literature. In the end, what makes a good book is something readable, well written, well planned, something enjoyable and something that appeals to a mass audience. Language transcends all those things so in the end it's the literature itself that needs to stand up to the test of being an international bestseller rather than any language barriers.