What are the best languages to learn for a future businessman?

I currently speak fluent Spanish and English and I don’t believe the massive effort to learn and retain Chinese will be worth it because I don’t believe all the hype about China being the next super power unless they revamp their political system.
That said, What would be the best languages to learn? I was thinking either French because it’s a big world language, German, maybe Arabic (depends on how Dubai does) or Russian( might be good to know in the future)