Through the centuries, humans have demonstrated extraordinary inventiveness in finding ways to extract confessions from foes. One of the most enduring means of coercion, dating at least to the days of the Spanish Inquisition, is a method that was long known as water torture.
It comes down to the simplest of elements: air and water. And the most elemental of emotions: fear.
Now known colloquially as waterboarding, the tactic has hopscotched across conflicts and cultures. Once again, it has made the leap from medieval parchments to TV screens, as President Trump signals he may seek to revive its use.
In modern times, waterboarding is so named for the board, angled downward...