Sen. John McCain (R-Ariz.) who was held prisoner during the Vietnam War, spoke on the Senate floor in support of the release of a report on harsh interrogation techniques used by the CIA during the Bush administration.

In a powerful address (video above), McCain said he knows from personal experience that torture produces more bad intelligence than good, and called the interrogation methods a "stain" on our national honor.

"I know [victims] will say whatever their torturers want them to say if they believe it will stop their suffering," said McCain.

He called out the method of waterboarding specifically as an "exquisite" form of torture, describing it as "shameful and unnecessary."

"Contrary to assertions made by some of its defenders and as the committee's report makes clear, it produced little useful intelligence to help us track down the perpetrators of 9/11 or prevent new attacks and atrocities."

McCain said the United States has always believed that even its enemies "possess basic human rights that are protected by international conventions the United States not only joined but for the most part authored."

He said terrorists "act without conscience, but we must not."

"We gave up much in the expectation that torture would make us safe. Too much," said McCain, pointing out that conventional interrogation methods were used to eventually hunt down Usama bin Laden.

McCain argued that using torture techniques is an "insult" to intelligence officers who have obtained good information without inflicting pain or degrading.

And he asserted that it's an insult to claim we cannot win the war on terror without resorting to torture.

McCain concluded with the following words: 

But in the end, torture’s failure to serve its intended purpose isn’t the main reason to oppose its use. I have often said, and will always maintain, that this question isn’t about our enemies; it’s about us. It’s about who we were, who we are and who we aspire to be. It’s about how we represent ourselves to the world.

We have made our way in this often dangerous and cruel world, not by just strictly pursuing our geopolitical interests, but by exemplifying our political values, and influencing other nations to embrace them. When we fight to defend our security we fight also for an idea, not for a tribe or a twisted interpretation of an ancient religion or for a king, but for an idea that all men are endowed by the Creator with inalienable rights. How much safer the world would be if all nations believed the same. How much more dangerous it can become when we forget it ourselves even momentarily.

Our enemies act without conscience. We must not. This executive summary of the Committee’s report makes clear that acting without conscience isn’t necessary, it isn’t even helpful, in winning this strange and long war we’re fighting. We should be grateful to have that truth affirmed.

Now, let us reassert the contrary proposition: that is it essential to our success in this war that we ask those who fight it for us to remember at all times that they are defending a sacred ideal of how nations should be governed and conduct their relations with others – even our enemies.

Those of us who give them this duty are obliged by history, by our nation’s highest ideals and the many terrible sacrifices made to protect them, by our respect for human dignity to make clear we need not risk our national honor to prevail in this or any war. We need only remember in the worst of times, through the chaos and terror of war, when facing cruelty, suffering and loss, that we are always Americans, and different, stronger, and better than those who would destroy us.

Watch the speech above.