What language to learn?

Joint posted at ComingAnarchy — weigh in with comments there.

I’m going to repost as an independent post something I first wrote as a comment four years ago regarding languages, and what languages to learn. I was reminded of this topic because of my co-author Younghusband’s post on preparing your child for the ComingAnarchy, as I wrote my first comment based on what languages I wanted my kids to study.

With regards to prioritizing language education, I consider five languages to be in the “first tier.” To rank them in general order of importance:
# English (North America, Britain, Australia, Singapore, New Zealand, India, Hong Kong, most international cities: The international language, hands down.
# Spanish (Spain, Latin America, large US cities): A language used broadly in the Western Hemisphere and increasingly in the United States.
# Chinese (China, Singapore, elsewhere): Not yet used much outside China, but a language spoken by a billion people with real potential to become an international language in the 21st century.
# French (France, much of Africa, Quebec, Iran): It’s international prestige is shrinking, but it remains popular in many former French colonies, and a vital language if you are working with any business that has any connection to France, due to the preference of the French to speak their own language.
# Russian (Russia, former USSR, former satellites): The Russian language will shrink in importance as former satellites move to other, more international languages — Mongolia being one example. But for now, it remains the language of intercultural communication in places such as Kazakhstan and more useful than Turkish, which may well replace it in the coming decades.
These languages have intercontinental importance. All but Russian will stay in the top tier for the rest of our lifetime.

The second tier covers languages that have broad Second tier:
# Arabic (Middle East, North Africa): Arabic is the only language that is a language of the United Nations that is not in my first tier because it’s relatively provincial. Despite its geographic reach from Morocco to Iraq, it is not used outside that region, and is almost irrelevant in business except in the provincial Arab sense. You can get away speaking French or English in much of the Arabic world.
# Portugese (Portugal, Brazil, Angola, Numibia, Macau, East Timor, other nations in Africa): Portugese is a major language because of Brazil — otherwise it would be ranked in a nebulous 4th tier together with Dutch.
# Japanese (Japan; other metropolitan areas of Asia): Japanese is, believe it or not, widely used in cosmopolitan, connected cities in Asia, and I’ve used it to speak with people in Thailand, Singapore, Korea, and China. In my own personal experience, I have spoken more Japanese than English in the shopping malls and tourist areas of Seoul. Add to that fact that Japan is the world’s number 2 economy and the Japanese have poor English language skills.

Then we have languages in the Third Tier that are used broadly in certain cross-border regions
# Turkish (Turkey, adaptable to Central Asian languages)
# Farsi (Iran, Tajikistan, Los Angeles)
# Punjabi or Hindi (Much of South Asia)

But all of this is opinion. Does anyone else want to weigh in with additional comments?