CHILD SOLDIERS OF AMERICA, REALLY?

ICHEOKU says does America have problem of child soldiers? If 18 year olds are allowed to enter into the country from the Southern border as "unaccompanied minors" and the same age group are recruited into the military as soldiers, what does that say about America? Therefore, it is either there is a political hypocrisy here where those entering the country are not necessarily "minors" or America engages in child soldiers.