Belligerent children, as a title, is an oxymoron. That is because children are, by nature, gentle and mild tempered. Only when there is negative interference by an adult, do they absorb some of the personality characteristics of the adult.
If your child is not sweet and mild tempered, you must get to the source of the problem instantly, and be aware that there is likely to be an adult involved. The Lord God Almighty is a God who needs every problem solved. He needs it solved as soon as you become aware of it. He needs it solved now.