The decision by the United States Supreme Court to abolish the death penalty for juveniles under the age of 18 is rightly seen as a landmark judgment. It should be a step on the way towards abolishing this barbaric punishment in the US, as has been done in many other states around the world - notably in the European Union, where this is a condition of membership.
Of the 39 executions of juveniles that have taken place since 1990, 19 have been in the US, with the remainder being in Iran, Nigeria, Pakistan, Saudi Arabia, Yemen and the Democratic Republic of Congo.
All these countries now regard the practice as illegal or have put it under review, bringing them into line with the United Nations Convention on the Rights of the Child. Only the US and Somalia have failed to ratify this convention. Nevertheless, several of the states mentioned are excoriated for human rights violations in the latest edition of the US state department's human rights report.
This judgment touches on core values within US domestic politics and concerning its relations with the rest of the world, as is clear from the dissenting opinions of the four minority justices against the five majority ones. The judgment refers to juveniles being "categorically less capable" than adults. It finds that the death penalty conflicts with the eighth amendment of the constitution outlawing cruel and unusual punishments.
It takes account of evolving standards of decency, refers to an emerging national consensus on the subject and acknowledges "the overwhelming weight of international opinion against the juvenile death penalty". It says the state cannot extinguish the appellant's life in the case it was considering and "his potential to attain a mature understanding of his own humanity" - despite the despicable murder of which he was convicted in 1993 at the age of 17.
Arguing against the judgment, Justice Anton Scalia rejects most of these grounds and is particularly scathing about reference to international law and law in other states, which, he says, cannot determine US legal sovereignty. In rejecting such an approach he echoes many members of the Bush administration and its supporters, who support the death penalty.
They are determined to rein in "activist" interpretations of the law by replacing liberal members of the Supreme Court with conservatives. Since there are likely to be several vacancies over the next four years this is a realistic prospect, assuming the US Senate approves such nominations.
There are some 3,500 prisoners on death row in the US. While capital punishment is banned in many of its states, it remains a lamentable symbol of US exceptionalism.