[Ouisch]

Back in the 1980s I remember reading all the dire warnings of how Japan was poised to be the world's number one economic superpower, and that all savvy business people were learning to speak Japanese. Some high schools even started offering it as a foreign language course (usually in the US our choices for foreign language classes are French or Spanish).

The Japanese furor eventually subsided, and next we were warned that we'd best start studying Arabic, because that would soon be the international language for business. Now it's recommended that school children start learning Chinese if they plan to compete in the global economy when they're older...

I don't doubt that it would be beneficial to learn Mandarin as a second language, but since the native speakers are concentrated in such a specific geographic region, versus English speakers spread all around the globe, I don't know that it will ever become the world's de facto second language.