There is just one threat to English as the world’s lingua franca, and it is not Mandarin. It is not even the (overrated) potential of translation technologies. It is the language’s own descent into bullshit.
A neologism: Gom-bling -- an ostentatious display of wealth with Irish characteristics, such as might be designed by today's version of the Gombeen Man. See, e.g., the Skypool in Embassy Towers, with Ballymore as the developer.