Donald Trump thinks the United States isn't demonstrating its strength enough in the fight against the Islamic State. One of his proposed solutions as president is to revive waterboarding, an enhanced interrogation technique that was used on terrorism suspects following the Sept. 11 attacks.
Barack Obama had officially discontinued the tactic because it simulates drowning and is considered to be a form of torture.
"I would bring back waterboarding, and I'd bring back a hell of a lot worse than waterboarding," he said at a Feb. 7, 2016, primary debate.
WHY HE'S PROMISING IT
The fact that terrorists know the United States doesn't waterboard puts the country at a disadvantage against the Islamic State, Trump has argued.
"They're chopping off heads and drowning people in big steel cages, and we can't waterboard, okay?" he said in an April 2016 interview with Fox News host Sean Hannity.
There is no concrete evidence that waterboarding is effective at extracting information. Further, there is scientific proof that techniques like waterboarding affect brain function in such a way that the person under interrogation is no longer reliable.
While Trump believes that waterboarding works, he has said that "if it doesn't work, they deserve it anyway, for what they're doing."
WHAT NEEDS TO HAPPEN
Torture is already illegal in the United States, but President George W. Bush's administration justified waterboarding and other enhanced interrogation tactics with legal maneuvering.
Amid the backlash against these interrogation practices, Obama banned specific interrogation tactics — including waterboarding — with an executive order in 2009, and Congress turned that executive order into law in 2015.
If the Trump administration wants to waterboard and do it legally, he would have to repeal Obama's executive order and get Congress to change the law. He also would have to find a way around international laws against torture, the constitutional ban on cruel and unusual punishment, and more, said Karen Greenberg, an expert on torture and director of Fordham Law School's Center on National Security.
She added that the United States currently does not detain and interrogate many high-value targets — they kill the targets instead — so reviving Bush-era enhanced interrogation would be irrelevant in that context.
WHAT'S STANDING IN HIS WAY
Beyond certain legal challenges Trump would face, there's plenty of political pressure against waterboarding. The law limiting enhanced interrogation had strong bipartisan support.
So there likely would be blowback from Republicans such as Sen. John McCain of Arizona, who said in November, "I don't give a damn what the president of the United States wants to do. We will not waterboard."
And Trump might also face resistance from career military and CIA agents, as well as lawyers from across the political spectrum who see waterboarding as indisputably illegal.
Mike Pence said he wouldn't rule out waterboarding as vice president, and Trump's pick to replace Brennan as CIA director, Rep. Mike Pompeo of Kansas, has said the post-9/11 enhanced interrogation tactics were lawful.
In the weeks after the election, Trump seemed to be less committed to his waterboarding promise, saying he was surprised to learn that his pick for secretary of defense, Ret. Marine Corps Gen. James Mattis, does not think waterboarding is a high priority.