child-marriages how is this allowed in usa?

8.24: news.psy/child-marriages/how is this allowed in usa?:
time.mag 6.12 p15:
. 17-year olds can join the military;
thus they should be able to marry before then,
to start their family before they get killed.
. most laws are based on parental rights,
[and many parents feel their children are sexual
and it safer to get them married
so that at least the unavoidable sex will be legal
(sex with your under-age wife is perfectly legal
while other under-age sex is statutory rape).]
. a problem with under-age marriage
is that in some states,
the under-aged cannot retain a lawyer
and thus cannot file for divorce
or fight for custody of their kids;
"legally, a 17-year-old is the same as a 7-year-old."
-- Fraidy Reiss, Unchained At Last