I'll give you some reasons: - Child soldiers should not be punished for their crimes because they are children, and were probably forced into war. - Children in war should be illegal because it is immoral to send under-developed people into something they probably cannot comprehend. - The children will be scarred and suffer from illness after war. - They are more defenseless and helpless than adult soldiers. - They do not pose as big as a threat as adult soldiers, either for their size, intelligence, etc.