I have many issues with what the USA does and how it sees itself, but this is not a personal attack on the USA and I hope others would not see it as such. If I had any issues with the UK, and I do, I would do just the same, as I would regarding any other country. As I've probably mentioned several times, it is all about the rights of the child versus those of the parent.
There is one thing in common with many in the list I gave - the rights of children. Child marriage - a bit obvious this one, being the right to self-determination over the right of the parent to treat them as their property, and child marriage has been outlawed by virtually every civilised nation. The physical chastisement of children (smacking, spanking, etc.) is again the right of the child not to be treated so when doing this just tends to send out the message that physical violence is appropriate, and often just isn't effective. Many countries do regard this as physical abuse and have banned this. The free health care, or a nation-wide 'free' health service should again impact children but I'm not that au fait with the system in America specifically regarding children. The relatively free access to weapons like guns will be having an affect too, as the recent shooting showed, as well as the numerous deaths caused by children or of children, such that just having so many guns around increases the chances of children being killed or injured, so raises the threat level rather than makes their lives safer. And the numbers of deaths related to guns alone surely will be having an affect on their lives. The obesity point - much like many other countries though - where children have the right to continued health, and we do know that obesity is linked to various health issues. And lastly, circumcision - the right not to have their bodies violated before they are able to decide for themselves, when it is the parental right seemingly advocated as trumping their rights.
The USA is hardly the biggest villain when it comes to the rights of the child, but as can be seen, the rights of the child are all too often in conflict with parental rights, whether that stems from culture or religious beliefs. That was my point.