Why are other countries so interested in speaking American English?

Answer 1

It used to be the other way around, i.e. that British English was the language of choice. But that was more than 50 years ago when the British empire spanned almost half the globe. Today, the empire is gone and its population is only 20% of that of the US while America is the lone superpower and its economy (at $19.6 trillion GDP) dwarfs that of the UK ($2.7 trillion). So it makes sense to learn the language which is most commonly used.