To truly end torture we must do more.

President Obama did the right thing in signing orders to close the detention facility at Guantanamo Bay and end the use of secret CIA prisons. But if we do not establish a truth commission (or some other investigative body) to examine the United States’ use of torture, the mistakes of Abu Ghraib, Guantanamo and elsewhere will continue to haunt us.

A 9/11 style, non-partisan truth commission will take a critical step towards effectively banning torture for good by establishing a comprehensive record of what went wrong and the true costs of previous policy.

To date, the United States has not conducted a full investigation into the use of torture by U.S. forces and security agencies. No one has stepped back to try and see the full picture, and to calculate the losses–in moral authority and American lives–of our national detour to the dark side.

Investigations have been conducted within agencies, rather than across them. Many have been hampered by a lack of authority and a lack of credibility. If we are truly going to fix this problem, we first need to have a full understanding of what went wrong.

If the commission were able to do its work effectively, and present its findings publicly, it could effectively end the debate over the use of torture in this country. With Human Rights First, I have started a group on Facebook to show support for creating a truth commission to investigate torture. Please join.

Right now the country is divided over the use of abusive interrogation techniques. Support for torture lingers. And some believe, as former Vice President Dick Cheney recently warned, that a future terror attack on America will be President Obama’s "responsibility" because he took action to end some of President Bush’s detention and interrogation policies.

One of the questions the commission would have to explore is: did torture work? Former CIA director Michael Hayden says that water-boarding and other forms of torture caused detainees to reveal critical secrets.

I do not believe that the use of these techniques was necessary or effective. I have come face-to-face in the interrogation booth with insurgents and Al Qaeda operatives. It is possible to make almost all of them talk using techniques that are lawful.

When I served as an interrogator, I did not mistreat detainees. For me, this was an issue of efficacy as well as morality. Everything I know tells me that torture is much more of a destructive technique than a useful "tool."

I am aware of too many cases where torture – or abuse – backfired. Just to cite one: a previously cooperative and truthful detainee named Al-Libi was taken by the CIA to be tortured in Egypt. Under duress he claimed that there was a connection between Al Qaeda and Saddam Hussein. This information was rushed to Secretary Colin Powell who used it in his speech to the United Nations as a justification to go to war with Iraq. Al-Libi later recanted, and all of his information – both when he was cooperative and later when he was tortured – were deemed tainted. It was determined that he made up the connection in order to make the torture stop.

I believe a thorough review of the cases where detainees were water-boarded or otherwise abused for intelligence purposes is warranted. I suspect we will find the evidence that they provided is of no more value than the evidence provided by Al-Libi or that the evidence could have been collected in a more humane, less destructive fashion.

In determining how "effective" torture may have been, the commission will have to also consider the strategic consequences of employing techniques that are, to quote Senator John McCain, "un-American." It ought to be possible to conduct a sophisticated cost-benefit analysis that examines the unintended consequences related to our actions. We know, for example, that Abu Ghraib was a boon to Al Qaeda recruiting. How much does the use of these "tools" undermine our efforts?

In order for this commission to be successful it must be made up of members with unimpeachable integrity who do not have a point to prove. It also must be armed with subpoena power. This commission must have the power — and the political will — to follow this story wherever it goes.

This is too important to leave half-finished. Though the President has taken action that will make us safer, questions linger that need to be answered.

Our country’s greatness is supported by our willingness to take a serious and thorough look at our mistakes. While it may be unpleasant, not doing so would compound the error, and increase the chances that it will be repeated. If we do not take action the public debate over the use of these techniques will continue to surface. Our allies and our enemies will see us as a hypocritical nation that only lives up to its ideals when it is convenient. And future generations will look back and wonder why we looked the mistakes of the past square in the eye and blinked.

Torin Nelson is the President of the Society for Professional Human Intelligence. He is a sixteen-year veteran interrogator and Human Intelligence specialist. Among other locations he has served at Guantanamo Bay, Abu Ghraib and the Bagram Air Base in Afghanistan.