The death of language?

"If we are not cautious about the way English is progressing it may eventually kill most other languages." (Claude Hagege)

The above is from "The death of language?". I think that the point is the relationship between the English language and the other languages.

I feel that my native language, Japanese, is falling into decline in some academic areas as a written language. The English language, as a spoken and written language, might also be falling into decline by its diffusion across the world.