The United States stands virtually alone among constitutional democracies in its use of capital punishment. This helps explain why, from time to time, our attachment to the death penalty, or particular executions, draws international attention and condemnation.

The latest example happened last week when experts affiliated with the United Nations’ Human Rights Council spoke out against Alabama’s planned use of nitrogen hypoxia to execute Kenneth Smith on January 25. This execution method is intended to deprive the condemned of oxygen by using a face mask connected to a cylinder of nitrogen.

Smith, who was convicted and sentenced to die for his role in a murder for hire committed in 1988, would be the first person ever to have their death sentence carried out using that method. But this will be the second time Alabama has tried to execute Smith.

As an article from Reuters notes, he is “one of only two people alive in the U.S. to have survived an execution attempt after Alabama botched his previously scheduled execution by lethal injection in November 2022 when multiple attempts to insert an intravenous line failed.”

Proponents of nitrogen hypoxia describe it as a “more humane option” for putting condemned prisoners to death than lethal injection and compare the method to the way that passengers on a plane will pass out when the aircraft depressurizes. As Michael Copeland told the Oklahoma legislature in 2015 during that state’s consideration of using nitrogen in executions, “The condemned person might not even know when the switch to pure nitrogen occurs, instead he would simply lose consciousness about 15 seconds after the switch was made. Approximately 30 seconds later, he would stop producing brain waves, and the heart would stop beating about two to three minutes after that.”

But others believe that the method cannot live up to that claim and risks going seriously wrong. What Richard Dieter, formerly with the Death Penalty Information Center, said in response to Copeland’s claims in Oklahoma is also true of Alabama’s plan, namely that the state would be conducting an “experiment” if it uses nitrogen hypoxia.

“This method,” Dieter explained, “has never been used before in an execution. I think it’s premature to accept a legislator’s promise that all will go well. It’s one thing to say that people have died of oxygen deprivation and another to strap an unwilling subject in a chamber and watch the reactions and resistance for the first time.”

Reuters also reports that “Smith’s lawyers have said the untested gassing protocol likely violates the U.S. Constitution’s ban on “cruel and unusual punishments,” and have argued a second attempt to execute him by any method is unconstitutional.” Commentators and death penalty opponents in this country agree and already have spoken out against what Alabama is planning to do in the Smith execution.

Now people in the international human rights community are joining them. They include Morris Tidball-Binz, who serves as the U.N. Special Rapporteur on extrajudicial, summary or arbitrary executions; Alice Jill Edwards, Special Rapporteur on torture and other cruel, inhuman or degrading treatment or punishment; Tlaeng Mofokeng, Special Rapporteur on the right of everyone to the enjoyment of the highest attainable standard of physical and mental health; and Margaret Satterthwaite, Special Rapporteur on the independence of judges and lawyers.

These U.N. officials are “concerned that nitrogen hypoxia would result in a painful and humiliating death.” They argue that “experimental executions by gas asphyxiation—such as nitrogen hypoxia—will likely violate the prohibition on torture and other cruel, inhuman or degrading punishment.”

In their view, “punishments that cause severe pain or suffering, beyond harms inherent in lawful sanctions likely violate the Convention against Torture to which the United States is a party, and the Body of Principles for the Protection of All Persons under Any Form of Detention or Imprisonment that guarantees that no detainee shall be subjected to medical or scientific experimentation which may be detrimental to his health.”

They also could have cited the Second Optional Protocol to the International Covenant on Civil and Political Rights (ICCPR) which, when it was adopted in 1991, called for total abolition of capital punishment.

Aa a news release from the U.N. Human Rights Office notes, the four U.N. officials have “appealed to Federal and State authorities in the United States and the State of Alabama to halt the execution of Kenneth Smith and any others scheduled to be executed in this manner.” Their statement and appeal made headlines here and abroad.

But they are not the only people from outside the United States who are raising concerns about Smith’s execution. The Rome-based Community of Sant’Egidio, a lay Catholic association dedicated to social service and the promotion of human dignity, weighed in last November.

It did so “to respond to Pope Francis’ appeal for Christians to work toward the abolition of the death penalty across the globe.” It invited people to send a petition to the governor of Alabama.

This Catholic group specifically targeted Alabama’s plan to use nitrogen hypoxia, which it said “is a gas which is not allowed even for the slaughter of animals, because it’s inhumane.”

In addition, the European Union has long framed its own opposition to America’s continued use of the death penalty in the language of international human rights. As it puts it, “The death penalty violates the inalienable right to life and is the ultimate cruel, inhuman, and degrading punishment.”

The EU also has called on the states in this country that “continue to practice capital punishment to establish a moratorium on executions, as a first step towards complete abolition.”

Like the U.N., Sant’Egidio, and the E.U., the distinguished death penalty scholar John Bessler says that America’s continued use of capital punishment violates international law. His argument applies with special force to Kenneth Smith’s case.

Bessler makes his case by comparing execution to torture. “International law,” he says, “prohibits torture.” As he explains, “The modern definition of torture under international law says torture is the infliction of severe pain or suffering, whether physical or mental, for a prohibited purpose such as punishment.”

Bessler points out that “psychological torture is such an inextricable facet of capital punishment,” and that “any debate about the death penalty should include the argument that the psychological trauma of being under a sentence of death—under a constant threat of execution—should be considered alongside the risk of physical pain that executions carry.”

If ever anyone had experienced the kind of torture and trauma that Bessler describes, it would surely be Kenneth Smith who, having survived an execution attempt using one unreliable method (lethal injection), now must contemplate being a human guinea pig as Alabama tries another one.

The whole world will be watching as this cruel experiment plays out. Many, here and abroad, will be appalled if it is brought to fruition.