Tuesday's botched execution in Oklahoma — where an inmate, Clayton Lockett, writhed on a gurney, staying alive for 43 minutes after receiving an untested cocktail of drugs until he succumbed to a heart attack — has reignited the debate in the United States over capital punishment and the supposedly humane methods by which it is administered. Lockett's physical reaction to the failed lethal injection was so sickening that prison officials closed the blinds so those in a viewing chamber would no longer bear witness to the grim scene.

The United States is the only major country in the Western world that still allows capital punishment, and the trend globally is, despite some setbacks, moving toward abolition. Amnesty International reports that in 2013 executions occurred only in 11 percent of countries worldwide, with 80 percent of the total taking place in three countries: Saudi Arabia, Iraq and Iran. (That figure excludes China — thought to be the world's biggest executioner — where exact, transparent data on capital punishment is unavailable.) Here's an Amnesty map on the decline of capital punishment globally.

The secrecy behind the chemicals administered to Lockett — which led to such an excruciating death — is the product of state laws meant to prevent the pharmaceutical companies involved from being harassed by activists and blacklisted by companies and governments elsewhere. Yet, despite the presence of death rows across the United States, it's still common for American commentators to look at executions elsewhere with a degree of contempt and fascination. Here are a few methods still carried out that could have given Lockett a swifter, more merciful death. (See my colleague Richard Johnson's chart at bottom for more global data.)

Beheading: Death by decapitation is a sentence associated with sharia law and carried out most conspicuously in Saudi Arabia. Last year, global attention was drawn to the case of a Sri Lankan maid controversially accused of killing an infant. Despite protests around the world and marches in her native country, she was beheaded with a stroke of a sword. It is unclear how many executions a year in Saudi Arabia are beheadings, but the number may be on the decline due to a supposed shortage of state-sanctioned swordsmen.

Firing squad: Death by firing squad is a practice on the books in many countries where capital punishment still exists. Firing squads have been phased out in the United States except for Oklahoma and Utah, where the last such execution took place in 2010. Some states are considering resurrecting the practice, given the continued controversy surrounding lethal injection.

Hanging: Hanging as capital punishment has a long, dark history in the United States, where lynchings, particularly of African Americans, were once commonplace. But it is perhaps the most widespread global form of capital punishment. It remains on the books in some U.S. states — the last execution by hanging took place in Delaware in 1996 after the inmate chose the noose over the needle.

Falling from a height: In 2008, reports emerged that Iranian authorities planned to throw two likely gay men accused of rape over a cliff, a rather medieval practice that dates to antiquity. The method is brutal and grotesque — but the victims' suffering would probably not have lasted as long as that of Lockett.