Obama did exactly that: he validated the practice by refusing to prosecute the perpetrators. Because he wanted to "look forward, not back."
And Digby gives us a grimly probable look at what comes after Obama (Donald Trump is bringing torture back: His entire foreign-policy team is comprised of big fans of the worst Bush-era practices Salon 11/18/2016):
And sadly, despite ending the practice upon taking office, President Barack Obama didn’t require any accountability for what had happened and the whole question was swept under the rug. Indeed, the administration fought the release of the Senate Select Intelligence Committee’s torture report and to this day has kept the full report under wraps. And so it became further normalized — never punished or fully repudiated — leaving it there for someone to come along and pick right up where the Bush administration left off.
Our next president is downright eager and excited to do it. He has proclaimed that he loves waterboarding, and has repeatedly promised to do “a lot more than that” as president. Despite all evidence to the contrary, he has insisted that it works and “if it doesn’t work they deserve it anyway for what they do to us.”
David Cole wrote about this problem six years ago to the date in Obama’s Torture Problem NYR Daily 11/18/2010. I think he was right in saying, "It turns out that looking forward, not back, will never resolve the torture legacy.... Torture and its after-effects will be with us until we are willing to confront them head-on."
The legacy of President Obama's decision to "look forward, not back" on the torture crimes will be with us for a long time.