At issue is book 47, verse four of the Koran, which says, "Therefore, when ye meet the unbelievers in fight [or jihad], smite at their necks at length." Another sura, or chapter, says: "I shall cast terror into the hearts of the infidels. Strike off their heads, strike off the very tips of their fingers."
But Georgetown's Esposito, author of What Everyone Needs to Know About Islam , maintains that while the Koran does have references to beheadings, they are part of a historical context. He also notes that if references in holy books are anything to go by, the Bible is replete with decapitations.
"The sword has been the common instrument for fighting wars, for fighting between individuals and also for executions," he said. "In the early days of Islam and Christianity, beheading was the common form of punishment — like lethal injection today."
Click here to read about some of history's infamous beheadings.
Beheading as a form of execution is part of the criminal legal code in Iran, Saudi Arabia, Yemen and Qatar. But in practice, only Saudi Arabia and Iran continue to decapitate criminals, although the number of beheadings in both countries has been declining.
‘I Still See Their Faces’
While state beheadings are widely condemned by international rights groups, experts note there are critical differences between judicially sanctioned decapitations that take place after a trial process — no matter how flawed — and the recent spate of beheadings of innocent civilians.
During his horrifying weeks in captivity, Kizil says it was the very capriciousness of his abductors that rattled him most. But astonishingly, the young mechanic says he would still go to Iraq "if somebody would guarantee my safety."
With a sick father, a large family debt and no employment available in the sinking Turkish economy, Kizil says he desperately needs the cash. "I would not recommend that my brothers go to Iraq," he said. "But I'm willing to go again to repay our debts."
The recent capture of laborers from mostly impoverished Asian and African nations has highlighted the growing threat to foreign workers in Iraq. In recent months, more than 60 foreign workers have been abducted.
From his home in Adana, Kizil says he relives his ordeal every time he hears news reports of abductions.
"I get nightmares, I feel threatened," he said. "I still see their [his captors'] faces. I remember how they beat me. … Twice, they put guns to my forehead and once they put a sword to my neck. I didn't think I had a chance, but I was spared. I hope others are also spared."