Hey Kiddo! Have you ever heard of the United Nations? It's a big group of countries from all over the world who work together to make things better for everyone. One of the things they do is called the Security Council, and they work to make sure that bad things don't happen around the world.
Now, they made a thing called "resolution 153" a while back. Basically, this resolution says that it's not okay for certain countries to sell weapons to other countries who might use them in a bad way. This is to try and prevent wars and make sure that innocent people don't get hurt.
It's kind of like when your mom tells you not to hit your little brother because it's not nice and you might hurt him. The United Nations is telling certain countries not to sell weapons to other countries who might use them in a bad way, because it's not nice and it might hurt a lot of people.
Does that make sense, Kiddo?