By Patricia Zengerle
WASHINGTON (Reuters) - A few dozen words rushed into law days after the September 11, 2001, attacks have been used to justify U.S. counterterrorism efforts from the war in Afghanistan to warrantless wiretapping and drone strikes, all on orders of the White House - and with little congressional oversight.
Now, as criticism grows that the law has been stretched well beyond its original intent to go after militant groups that did not even exist on 9/11, some Democrats and Republicans have begun writing legislation to update the nearly 12-year-old resolution.
That could restoke tensions between Congress and the White House over executive power, which were on display when Republican Senator Rand Paul staged a 13-hour filibuster in March to protest President Barack Obama's use of unmanned aircraft to conduct targeted killings.
"If you look back at the 60-word authorization that was put in place on September 18, 2001, and look at where we are today, there's a very, very thin thread, if any, between that authorization and what is occurring today," said Senator Bob Corker, a leader of the effort to examine the 2001 resolution. Its formal title is the Authorization to Use Military Force, or AUMF.
The top Republican on the Senate Foreign Relations Committee, Corker said he wanted to spell out the kind of counterterrorism activities that could be authorized, and to bring Congress back into the equation.
"Congress has totally outsourced its foreign policy oversight," he said in an interview. "And a lot of people like it that way. Congress can take credit if things go well, criticize if things don't go well, but in essence Congress has no ownership over what we are carrying out right now. That's not an appropriate place for Congress to be."
The AUMF gives the president authority to "use all necessary and appropriate force against those nations, organizations, or persons he determines planned, authorized, committed, or aided the attacks that occurred on September 11, 2001, or harbored such organizations or persons, in order to prevent any further acts of international terrorism against the United States by such nations, organizations, or persons."
It has no geographic limits or expiration date and, as such, has been the legal justification for drone campaigns in Pakistan and Yemen that have sometimes killed civilians and increased tensions among local populations.
In recent days, debates over U.S. national security policies have been roiled again by the Boston Marathon bombings, and a spreading hunger strike at the Guantanamo Bay prison for suspected foreign militants, which Obama pledged - and has failed - to close.
While opponents want the AUMF repealed, a group of more moderate legislators wants it adjusted to account for a changing world and to set precedent as other countries build their own counterterrorism - especially drone - programs.
It is not yet clear what a revised AUMF would look like. Some members of Congress want to spell out policies for conducting drone strikes. Many want its scope expanded to include militant groups not directly tied to or found to be "harboring" al Qaeda, including some operating in Africa, and to groups that target U.S. allies in its fight against terrorism.
Some say a "Son of AUMF" should include more controls, such as defining who can be detained and for how long, including U.S. citizens. Others said there should be some definition of when hostilities under the AUMF would end.
"The current AUMF is too broad, too narrow and too vague," Michael Leiter, former director of the National Counterterrorism Center, told the Senate Foreign Relations Committee in March.
Most presidents, Obama included, guard their war-making powers jealously. White House officials have suggested they are open to changes in the AUMF, congressional aides said. Publicly at least, they have not offered specifics.
Obama, who has pledged more transparency over U.S. drone operations, said in October, "One of the things we've got to do is put a legal architecture in place, and we need congressional help in order to do that, to make sure that not only am I reined in but any president's reined in in terms of some of the decisions that we're making."
White House officials had no immediate comment.
John Bellinger, then a legal adviser to Republican President George W. Bush's National Security Council, helped draft the AUMF "almost on the back of an envelope" when the ruins of the World Trade Center were still smoldering. Congress passed it three days after the attacks, and Bush signed it on September 18.
Bellinger said the measure needed an update. He noted, for example, that it was now being used to justify going after targets who were only 8 or 9 years old when the September 11 attacks occurred.
"It really is getting old," he said. "It was drafted extremely rapidly after September 11 and has covered a whole variety of different activities over the last 12 years that were not originally contemplated."
Bellinger, now a partner at the law firm Arnold & Porter, said there was a tension between those on the left - an important part of Obama's base - who want to cut the law back or repeal it and those who would revise it to provide authority to engage in more activities.
"If people ... were to delve into the legal theories, I think they would find that the administration is probably either really stretching the boundaries of the AUMF to cover some of the individuals or groups that they're targeting, or, without telling anyone, simply relying on the president's constitutional authority," Bellinger said.
Democratic Senator Carl Levin, the chairman of the Senate Armed Services Committee, said any effort to change the AUMF should be done carefully.
"It's a huge subject and there's not an easy answer to it. It takes a lot of thought and I myself have thought a lot about it, but I don't have an answer to (the question) if I could write a new AUMF, what would I say?" he said.
Democratic U.S. Representative Barbara Lee, the only member of Congress to vote against the AUMF in September 2001, said the intervening years had only underscored her original concerns and intensified her desire for repeal.
"This has been I think a very dangerous resolution and it's given the executive branch just such broad authority that it has eroded our system of democracy and our system of checks and balances," she said.
(Editing by Warren Strobel and Peter Cooney)