The word language has been repeated three times for a reason. Speaking the language, showing you have taken or are taking the time to learn another language is the number one way to improve your chances of getting an overseas job. You may be Australian, have great friends in France and be a great systems architect but if you cannot speak French then you stand less of chance of getting that job in the Paris office over the person who speaks French. Even someone learning French has a better chance.
In short, if you want to leapfrog yourself into a job overseas go and learn a new language. You will not regret it.