Governments get a vast amount of money in the idea that the Earth is round, think of all the space programs of the world. All these get INSANE amounts of funding, to go to the moon, and develop this and that and the other thing. now if the Earth is actually flat, then that is not possible, hence, trillions of dollers are going to the government. There are other motives, but you can use the search function to find those if you dont believe me.
You put an embargo on a country to punish them, they broke the worldwide gov'tal conspiracy, they will be punished by sanctions upon the country. If they were to say that, you could make the point that they were spreading ignorance among their people, and given the amount of international policing that goes on today, something would probably come of that too.