It will need to be done step by step. When nations see how good and cheap this system is and how great are the education results they will be more willing to join.
I also think that AI can play a huge role in this - but for sure it needs to be improved.
Likely will need in-person teacher facilitation as well, setting up kids alone with a laptop and an AI feels very wrong and dystopian to me.
Edit: Also getting all nations to agree will be impossible, if not then you will probably a curriculum that suffers death by committee.