Health- I guess I deserved that. I apologize for my comment.
Honestly, I have no idea if we will “have the world” when Mashiach comes. The only thing I know, is that when Mashiach comes, we will have our government/kingdom in Eretz Yisroel, we will have a Beis HaMikdash, and there will be universal knowledge and recognition of God. Does that mean that will be the end of all other countries and there will be a new world order with the King of the Jews as the King of the World? I have no idea.