What is waterboarding?

In what shocks sensible people, US. Republican White House front-runner Donald Trump says he is open to harsh measures to deal with the threat from Islamic State, including going beyond the controversial interrogation tactic known as waterboarding.

In an interview on ABC's "This Week" program, Trump discussed reviving the tactic and implementing other interrogation techniques, pointing to the recent beheadings of Christians in the Middle East as evidence of the need for stronger interrogation methods for suspected operatives of extremist groups, reporters Reuters.

Waterboarding is the practice of pouring water over someone’s face to mimic drowning as an interrogation tactic. Critics say it is torture, and Democratic President Barack Obama banned use of the method days after taking office in 2009. Waterboarding was used by the CIA under the Bush administration during the early days of the wars in Iraq and Afghanistan in the aftermath of the September 11, 2001 attacks.

Its defenders say it helped to keep America safe by garnering more information from captives, but critics argued the method never actually yielded actionable intelligence. Water boarding has been around for centuries. It was a common interrogation technique during the Italian Inquisition of the 1500s and was used perhaps most famously in Cambodian prisons during the reign of the Khmer Rouge regime during the 1970s.

As late as November 2005, water boarding was on the CIA's list of approved "enhanced interrogation techniques" intended for use against high-value terror suspects. And according to memos released by the U.S. Department of Justice in April 2009, water boarding was among 10 torture techniques authorized for the interrogation of an al-Qaida operative.

Water boarding as it is currently described involves strapping a person to an inclined board, with his feet raised and his head lowered. The interrogators bind the person's arms and legs so he can't move at all, and they cover his face. In some descriptions, the person is gagged, and some sort of cloth covers his nose and mouth; in others, his face is wrapped in cellophane.

The interrogator then repeatedly pours water onto the person's face. The person's mind believes he is drowning, and his gag reflex kicks in as if he were choking on all that water falling on his face. Trump argues that the "evil" nature of modern times required more robust interrogation techniques, saying that US enemies are thriving in the absence of them.