LAST week at its New York headquarters the United Nations held its annual Treaty Event, which encourages country leaders to sign up to any of the organisation’s 550-plus conventions. This year the spotlight was on the Convention on the Rights of the Child, which has been adopted by every country apart from Somalia, South Sudan and America. Somalia is anarchic and South Sudan became a country only two years ago. What is stopping America from ratifying the treaty? The treaty was adopted by the UN General Assembly in 1989 and became one of the most rapidly and widely adopted human-rights pacts. It sets standards for education, health care, social services and penal laws, and establishes the right of children to have a say in decisions that affect them. America signed it in 1995 but never ratified it. (By signing a treaty a country endorses its principles; ratification means committing to be legally bound by it.) The bar for treaty ratification is set high in America: the president must send treaties to the Senate, where they require approval by a two-thirds majority, the same standard required to amend the Constitution. The child-rights convention has never made it to a vote. Although Presidents Clinton and Obama have supported ratification, opposition by Republicans in the Senate has made it clear that the treaty would not pass.

Opponents of the treaty say it would usurp American sovereignty, a long-standing fear about the UN among some conservative Republicans. There is a fear that the social and economic rights established by the treaty could provoke lawsuits demanding that the government pay for these things. To address such concerns, America generally ratifies human-rights pacts with the condition that they will not overrule existing laws. Parent-rights groups claim the treaty would undermine parents’ authority, particularly over religious and sex education. Michael Farris, head of one such group, ParentalRights.org, sees the treaty’s principle that governments’ decisions should be in the best interest of the child as a blanket permit for the authorities to override any parental decision that a government worker—such as a school official or social worker—disagrees with. Jonathan Todres, a law professor at Georgia State University, disagrees: he notes that the treaty promotes the family as the best environment for children and points out that 19 of the treaty’s provisions acknowledge the role of parents.

Most American laws are already consistent with the pact, but not all. A notable exception is that in America under-18s can be jailed for life without parole (until 2005, they could be sentenced to death). The treaty prohibits cruel and degrading punishment, so ratification might curb smacking. Although America has laws against child abuse, a third of states allow corporal punishment in schools and none bans it at home. America’s adoption of other human-rights treaties has helped to fill gaps in American law. Participation in the UN treaty on child soldiers, for instance, prompted America to abolish the deployment of under-18s in military operations. Ratifying the child-rights treaty could also improve America’s reputation as a champion of child wellbeing, according to Jo Becker of Human Rights Watch, a New York-based advocacy group: “It is awkward when the US tries to promote child rights in other countries—they all remind us that they’ve joined the treaty and we have not.”