Increased oversight designed to bring killing programme out of legal shadows as president defends use of strikes in the past
Special courts would be asked to decide on targeted assassinations of terrorism suspects under a clutch of new legal checks proposed by Barack Obama to bring an end to the notion of an "boundless war on terror".
The president, who currently has to personally sign off on targeted drone strikes outside the US, hopes the increased oversight will help bring his controversial programme of killings out of the legal shadows.
He also proposed that a smaller number of drone attacks in the future would be carried out primarily by the US military rather than the CIA, having first passed a new test to ensure that alternative options have been exhausted.
But the White House defended its decision to launch hundreds of such strikes in recent years, insisting they were more discriminating than other military options such as aerial bombing and had helped prevent terrorist attacks.
In a major policy speech outlining new US counter-terrorism doctrine, Obama also announced a series of steps he was taking to try to speed up the closure of the Guantánamo Bay detention centre – including lifting a blanket ban on the transfer of prisoners to Yemen and seeking a site in the US for military commissions to take place.
Obama said America was at a crossroads, having spent over a trillion dollars and 7,000 lives fighting wars over the last decade. "We must define the nature and scope of this struggle, or else it will define us," he said.
"To say a military tactic is legal, or even effective, is not to say it is wise or moral in every instance."
Though some of the policy details have been trailed, the speech at the National Defense University marks a softening of rhetoric too.
Despite continued attacks in Boston and London, Obama said the US should seek to address the "underlying grievances and conflicts that feed extremism" through greater foreign aid and diplomacy. He claimed that success in fighting al-Qaida leaders in Afghanistan and Pakistan meant the US had to think more about deterring home-grown terrorists in the future.
"In the years to come, not every collection of thugs that labels themselves al-Qaida will pose a credible threat to the United States," said Obama. "Unless we discipline our thinking and our actions, we may be drawn into more wars we don't need to fight."
Nonetheless, the policy measures announced by Obama remain limited. Transferring drone operations from the CIA to the Pentagon was a "preference" rather than a guarantee, said administration officials, in background briefings before the speech.
Obama also said he would ask Congress to review his proposal for future drone strikes to be subject to court review or an independent oversight board.
"The establishment of a special court to evaluate and authorise lethal action has the benefit of bringing a third branch of government into the process, but raises serious constitutional issues about presidential and judicial authority," he said. "Another idea that's been suggested – the establishment of an independent oversight board in the executive branch – avoids those problems, but may introduce a layer of bureaucracy into national security decision-making, without inspiring additional public confidence in the process."
The Bureau of Investigative Journalism estimates that between 240 and 347 people have been killed in total by confirmed US drone strikes in Yemen since 2002, with a further 2,541 to 3,533 killed by CIA drones in Pakistan.
Human rights campaigners cautiously welcomed the attempt to bring US drone warfare policy into the open, but called on President Obama to publish the new legal tests agreed this week but only seen by Congress.
Dixon Osburn, a director at Human Rights First, said: "On its own, it is not clear that taking things away from the CIA makes a difference – the special operations command at the Pentagon is also secret – but at least the military are schooled in the rules of war.
"It looks like Obama is trying to return his counter-terrorism strategy to something that operates within the law. We want to know what that legal framework is though."
Elisa Massimino, president of Human Rights First, said: "We strongly welcome the statement that our values and ideals are our greatest asset. It is a slogan that we have a heard a lot but it is good to finally hear a strategy for how you get there."
General Willian Nash, a veteran of Vietnam and Operation Desert Storm, and now an independent consultant on national security issues, added: "He has begun the transition from a perpetual war to a more normalised national security framework."
Earlier, the White House began its new effort to draw a line under the controversial drone-strike policy by admitting for the first time that four American citizens were among those killed by its covert attacks in Yemen and Pakistan since 2009.
Obama also said the fight against domestic extremists would pose new challenges in balancing civil liberties and announced plans for the Department of Justice to review how it protected journalists during the pursuit of classified leaks.
But in a swipe at his predecessor, George W Bush, the president said the war of terrorism had to come to an end if US values were to be preserved. "Our victory against terrorism won't be measured in a surrender ceremony on a battleship, or a statue being pulled to the ground. Victory will be measured in parents taking their kids to school; immigrants coming to our shores.. And long after the current messengers of hate have faded from the world's memory … the flag of the United States [needs to] stand for freedom."