International Human Rights Law as Barring Sentencing Murderers to Life Without Parole?

The New Zealand Herald reports:

Foreign Affairs officials are warning the Government that its hardline sentencing and non-parole policy risk damaging New Zealand's international reputation.

They say National's "no parole for the worst murderers" policy and the proposed "three strikes and you're out" law could breach international obligations on torture and civil rights.

The Ministry of Foreign Affairs and Trade says such breaches would affect New Zealand's ability to influence other countries.

The ministry's advice, obtained by the Herald under the Official Information Act, says passing the laws "would pose reputational risks to New Zealand by resulting in international criticism".

The ministry has told the Government that no parole for the worst murderers — a National election policy — would enable "indefinite detention without the possibility of release", and would probably violate two human rights conventions monitored by the United Nations.

Act's "three strikes" policy, which imposes a life sentence with a minimum non-parole period of 25 years on the third "strike" offence, "may result in disproportionate sentences that could also breach the human rights obligations assumed by New Zealand (and most other countries)"....

Depending on how three strikes laws are implemented, they may indeed be unwise and unjust. The same might even be true of life without parole for some murderers — consider someone who is guilty of a mercy killing, or of killing in revenge against a brutal attack on his child (when such a killing is planned over an extended time, it probably would be murder rather than manslaughter). These, though, would be rare cases, especially as to the "murderers with previous [violent] convictions" that seem to be involved in this situation.

But I would pretty strongly resist any attempt to have our laws on these subjects be governed by "human rights conventions" that chiefly represent the views of elite lawyers in Western countries rather than of American voters, constitution-makers, or even judges (who at least have been appointed and confirmed by American elected officials and could in time be replaced by American elected officials). I would hope that New Zealand would take a similar view.

It's also important to keep in mind that the "international law"-based argument against the death penalty wouldn't be limited just to the death penalty, and in fact might end up being deployed against the very punishment that is often urged as a reason why the death penalty is unnecessary.