To put this debate in context, I'd recommend a truly excellent book 'The Last Lingua Franca: The Rise and Fall of World Languages', by Nicholas Ostler, pd 2010. The author's view: 'The forces making for the spread of English will soon peak, and the sequel will be a long retrenchment, as auxiliary English comes to be less widely used, but no single language will take its place.'

I do think it's a mistake that languages are less widely taught in Australia than they used to be. I'm old enough to have learnt French, German and Latin at high school, and with that background can make sense of written Italian and Spanish. It's also easier to pick up extra languages, possibly because your brain is attuned to the possibility. No Asian languages were taught back then, which I regret, but I was once fluent in Tok Pisin (PNG) and I've learnt a bit of Mandarin and fragments of Aboriginal languages.

Also language teaching should be started in Primary school; it's no good throwing English monolingual students into Chinese at high school when they are directly competing with students who are already fluent in Chinese at home. The stats indicate that most Yr 12 Mandarin students have a Chinese background.