President Obama: 'I am not going to release individuals who endanger US people'
The US will find a way to cope securely with dangerous detainees at Guantanamo Bay, President Barack Obama has said.
He described Guantanamo as a "misguided experiment", but conceded some of those held still posed a threat to the US.
Some could be jailed in mainland US prisons, Mr Obama suggested, under a new legal framework for detainees that would see the camp close by early 2010.
Congress has rejected Mr Obama's move to fund the closure of Guantanamo, amid concern over moving inmates to the US.
Speaking afterwards, former Vice-President Dick Cheney strongly defended Bush-era security strategies.
He recalled the experience of being in a White House bunker during the 9/11 attacks and said this shaped the way he viewed his responsibilities.
And he defended the "enhanced interrogation" authorised by the Bush administration to extract information from terror suspects as "legal, essential, justified and successful".
Mr Obama's speech on Guantanamo was made against a backdrop of rising concern in the US Congress at the president's plan to close the camp by January 2010.
James Coomarasamy, BBC News, Washington
In a phrase that his political opponents are certain to seize on, Mr Obama said the techniques that were used in the Bush years were "not America". His one olive branch was confirmation that he would not support a truth commission looking into the past.
He recognised the practical difficulties in closing Guantanamo - and, while he avoided giving details of which detainees would be transferred and when, he took some time to lay out clearly the different categories of remaining prisoners: from the Uighurs, whom the courts have already ruled should be released, to the dangerous prisoners who won't be taken in by other countries.
He addressed the main concerns of Congress, with his clear commitment not to release prisoners onto US soil who pose a security threat to the country.
Speaking at the US National Archives, where the US Constitution and the Bill of Rights are kept, the president regularly spoke of the need to respect the rule of law, at one point calling the US "a nation of laws".
Mr Obama said the administration was reviewing every one of the 240 detainees still held at Guantanamo and considering what to do with them.
Where feasible, some would be tried in US civilian courts, he said; those who violated the laws of war would need to face a military commission; some had been ordered released by the courts; others could be safely transferred to another country.
The most tricky category, Mr Obama said, would be those detainees who could not be prosecuted but who posed a "clear danger to the American people".
Some detainees had received explosives training, or pledged allegiance to al-Qaeda, or made it clear, the president said, that they still wanted to kill Americans.
'No dangerous releases'
Telling his audience that he would not endanger American lives, Mr Obama said that nevertheless a new policy for this group, based in law, would need to be drawn up.
"We must have clear, defensible and lawful standards for those who fall into this category," he said.
"We must have fair procedures so that we don't make mistakes. We must have a thorough process of periodic review, so that any prolonged detention is carefully evaluated and justified."
We are not going to release anyone if it would endanger our national security
"As president, I refuse to allow this problem to fester. Our security interests won't permit it. Our courts won't allow it."
Twice during the speech he directly promised not to release potentially dangerous people onto the streets of the US.
"We are not going to release anyone if it would endanger our national security, nor will we release detainees within the United States who endanger the American people," he said.
Mr Obama's keynote speech was followed by remarks of a very different tone by Mr Cheney.
Dick Cheney said the Bush-era decisions had saved US lives
Mr Cheney, who has emerged as a strong critic of the Obama White House, addressed a Washington think-tank to lay out the "strategic thinking" behind the Bush administration's actions.
He began by saying that Mr Obama deserved cross-party support for wise decisions, but added that: "When he mischaracterises the decisions we made, he deserves an answer."
Mr Cheney recalled the dangerous hours on 11 September 2001 as he was shepherded to a White House bunker as hijacked airliners hit New York and the Pentagon.
He said the experience deeply affected him, and said the Bush administration's policies were dedicated to making sure no attacks of that kind could ever happen again.
Mr Cheney dismissed the "theory" that the use of waterboarding on terror suspects acted as a recruitment tool for those intent on attacking the US.
And he criticised attempts to change Bush-era terminology: even if the phrase "enemy combatants" was not used, Mr Cheney said, "the same assortment of killers and would-be mass murderers are still there".
"Finding some less judgemental or more pleasant-sounding name doesn't change what they are or what they would do."
US MEDIA REACT TO OBAMA'S SPEECH
Obama's speech this morning, like most Obama speeches, made pretty points in rhetorically effective ways about the Constitution, our values, transparency, oversight, the state secrets privilege, and the rule of law. But his actions, in many critical cases, have repeatedly run afoul of those words.
Obama's is the speech of a young senator who was once a part-time law professor - platitudinous and preachy, vague and pseudo-thoughtful in an abstract kind of way... he's more comfortable as a debater, not as someone who takes responsibility for decisions.
This speech, to my mind, was a conservative one by a conservative president who seeks first and foremost to use existing institutions to address the new challenges of the moment, and then seeks pragmatic compromises, always open to future checks and balances, in those places where such institutions clearly need reform and adjustment.
Obama found himself in a real jam about Guantanamo. He and the rest of the Left had made a bogey of it... Well, Obama wins the election, and he finds that Guantanamo does the job... But he is stuck with his original language and assertions. What to do? You can't admit error; you can't cut the Bush administration any slack. So you cover Guantanamo with a fog of words... I think that is what Obama has done in this speech.
It's not an argument that can be boiled down to a bumper-sticker slogan, but it's not so complicated, either, and I think it's an effective rejoinder to his critics. He's basically saying, Look, we've got to do something so if you don't like my idea, come up with a better one. But we can't keep doing the same thing. It effectively puts the ball back in his critics' court.
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