Originally Posted by
JDNSW
But one that has plenty of historical precedent, although not historically for the whole world, due to poorer communications.
Some of the early examples are where Aramaic displaced most languages in the Middle East, largely being succeeded by Greek, and later Arabic and Turkish. Further west Latin displaced most other languages and became the "world language" for the Western world, only to be largely displaced by French. Further east Mandarin became dominant, and Malay further south, although South and southeastern Asia never gained a common language to the extent that occurred in Europe. Northern Asia had most local languages replaced by Russian.
In the Americas, all local languages were largely replaced by English, Spanish and Portuguese. In the British Isles, English was almost completely universal by the mid twentieth century, and the worldwide british Empire spread the language worldwide.
Today, the economic and political dominance of the USA, building on top of the language legacy of the British Empire, has meant that ability in English has become a key to personal advancement in almost every country in the world. It is possible that this may be challenged by Mandarin in the future, but I would not bet on it.
Whether the increasing dominance of English, that I have observed during my lifetime, continues, largely depends on what happens in world politics rather than anything to do with education or what governments want!